upgrade slow old tower pc

Nowadays pc market is dominant by mobile devices such as laptop and smartphones. Those old tower pc appears to be slow down. Don't throw them away, these tower pc has plenty of room to upgrade. First of all, let's analyze the bottleneck. In windows Cntr + Alt + Delete will brings up the task manager, where you can see which hardware or service need to upgrade.

If your memory is 100% busy all the time, you need a better memory.

If the disk is 100% busy all the time, your processes have used all the disk read/write bandwidth. Before you get a faster hard disk, try to get rid of the applications that use lots of disk I/O, scan virus, run disk check/fix tool. Sometimes, the memory is the true bottleneck, but your operation system may use hard drive to cache data to save memory. As a result, most of the time is waiting for disk I/O instead of waiting for memory. So use judgement here. Change disk may not help, you may want to add memory instead. However, change disk will help if the software is the problem. After reinstalling operation system, anti-virus, needed softwares via the correct channel, the system start new and clean, the software related bottleneck should be fixed.

If the network is 100% busy, you need a better network card or better internet service. Again, google "network speed", choose a website to have your actual network upload/download speed tested before buying anything.

Well, if the cpu is almost 100% busy, you have to get a solder in order to change the cpu from the mother board, doable but may not worth the hassle, it is outside the scope of this post.

Once we know the bottleneck hardware, we need to buy the replacement. For example, to find the hard disk model number. Simply click on Start and type “msinfo32” in the search bar. Once you've hit Enter, the System Information window will open. Click on Components in order to expand the list, then select Storage, and click on Disks in the expanded Storage menu. You will see your hard drive's specifications, among them the model number.

The next task is to search in amazon, ebay, craglist, newegg, google, etc. to buy the matching hardware.

Once the hardware arrives, you need to shut down the computer, unplug the power, open the case with a screw driver. Take a picture of the wires before you start, so that you can plug them back to the right place once you are done. Find the hardware looks like what you just bought, take a picture, before you loosen the screws, pop out the thing, unplug the cables, so that you know how to put them back once you swap the thing you want to change. The process usually took less than half an hour.

After you plug things back, including the power cord, you press the reset button, then should hear beep when the computer start, and primitive texts showing on the monitor screen. If nothing showing on the monitor screen, check the monitor cables.

If you are replacing hard disk, get your original operating system CD ready. Occasionally, when installing windows 7, we will get blue screen of death "Stop Error c000021a", it can be fixed with the following steps:

• press reset button on the computer
• after restart press and hold F8 key
• In the advanced boot options, select last known good configurations (advanced)
• hit enter

Once windows 7 is installed, we can upgrade to windows 10.

How to setup VPN Server at home

If you have a PC with windows XP professional and a router supporting port-forward, then you can setup a VPN server at home without cost a penny.
Even PPTP based VPN is criticized for low security compared with L2TP/IPSec based VPN, Microsoft Inc. is constantly promoting it. The PPTP VPN client is included by default in all versions of windows XP, windows vista. If you have windows XP Professional, you can even set up a PPTP based VPN server at home. The good side is PPTP based VPN setup don’t cost you a penny, and functioned the same as those expensive cisco gateway backed VPN setup; the bad side is, you should be aware of the security issue facing the PPTP VPN — for PPTP the authentication process is not done over secured connections hence credentials can be lost to hackers and thus they can have access to the VPN server. The secure connection is setup only after the authentication is done.
To set up VPN, you should do three things.
Task #1: Having a router supporting port-forward. (Here is a farely completed list for routers supporting port-forward. My recommandation is LINKSYS WRT54GL. It is a perfect router for someone with networking experience who wants an inexpensive router to do expensive networking tasks.)
Task #2: Configure your router so that the traffic at your router’s port TCP-1723 will be forwarded to the local IP address of the PC running your VPN server software.
Port Forwarding How to
Task #3: Enable and configure the VPN server software at that home PC.
Simple PPTP VPN Server Setup in Windows XP
Now, the VPN client on the internet can access your VPN network anywhere, the only thing the client need to know is your router’s external IP address (which is dynamically assigned by your ISP) and the password of your VPN (of course). The IP address may change now and then, so your VPN client need to adjust the IP address accordingly.
If updating the dynamic IP address annoys you, you can ask a software to do this for you.
This is how to: firstly bind the dynamic IP address to a domain name, then point your VPN client to the domain name, so that no update is needed at the client side. At the server side, a software periodically tests your external IP address, then binds the new IP address to the domain name. no-ip.com have already wrote such a software for you, they even provide free domain name! If you are a hard-core programmer and dare not trust the softwares downloaded from the web, writing a software in Java or C++ is not that hard.

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How to remote contorl your LAN computers

If you have followed my previous posts on how to set up workgroup and file sharing in your home network.

You maybe commuted between your computers to configure, debug, inspect results... What a hack...

How nice if we can sit on one computer and remote control other computers without physically walked there. Fortunetly, we have a very easy solution with VNC server.

"VNC is remote control software which allows you to view and fully interact with one computer desktop (the "VNC server") using a simple program (the "VNC viewer") on another computer desktop anywhere on the Internet. The two computers don't even have to be the same type, so for example you can use VNC to view a Windows Vista desktop at the office on a Linux or Mac computer at home. For ultimate simplicity, there is even a Java viewer, so that any desktop can be controlled remotely from within a browser without having to install software."
To set up VNC server-client connections.

Download and install RealVNC (Free Edition is good enough) from

http://www.realvnc.com/products/download.html

SelectVNC Free Edition for Windows
Installer including both Server and Viewer
Follow the install wizard, which will show you how to configure a vnc server on your computer so that other computers can remote control your computer after login with password. The wizard also installs a vnc viewer, so that you can remote login and control other vnc-server installed computers.

After installing vnc servers and clients on all your home computers.

Sit in front of one of your pc, Click START -> All Programs -> RealVNC -> VNC viewer 4 -> Run VNC viewer

In the server text box, type in the IP address of the remote computer and click OK. In the next screen, input the correct password and click OK.

Walla, magic.

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Enable File-sharing in windows xp

In my previous post, I have set up a workgroup on windows xp computers. In this post, I will go through a few steps to enable the simple file sharing.

Step 1, enable simple file sharing.

For winxp pro:

Double click My Computer -> Tools -> Folder Options -> View -> make sure "User simple file sharing [Recommended]" is checked.

Step 2, modify shared documents properties.

For winxp Home Edition:

Double Click My Computer -> Right Click Shared Documents -> Click Sharing tab -> Check "Share this folder on the network" and "Allow network users to change my files".

For winxp Professional:

Double Click My Computer -> Double Click Shared Documents -> Right Click the folders you want to share and change the Sharing properties one by one.

Now go to START -> My Network Places -> Viw workgroup computers -> Double Click the computer in your workgroup, the shared folder shows up. You can copy/paste or drag/drop files from/to that remote folder.

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Windows workgroup debug "User has not been Granted the Requested Login Type"

In my previous post, I demonstrated how to set up windows workgroup.

Setting up windows workgroup is easy, only if you are lucky enough.
The most common error message ppl bumped into is:

"\\xxx is not accessible. You might not have permission to use this network resource. Contact the administrator of this Server to find out if you have access permissions."

A lot of reason can cause the above error message.

1. Check the firewall settings (it may even prevent you to ping through).

Go to START -> Control Panel -> Securety Center -> Windows Firewall -> Select OFF

and see if the error gets fixed. If so, you may turn on firewall and change the firewall exceptions.

2. Make sure user "Guest" is enabled.

Go to START -> Control panel -> User Accounts -> click User Accounts -> Make sure Guest is turned on.

3. For windows xp pro, you may need to modify the Local Security Policy to allow the Guest to access the computer from network.

Go to START -> Control Panel -> Performance and Maintainance -> Administrative Tools -> Local Security Policy -> Local Policy -> User Rights Accessment

Find the key "Deny access to this computer from network", double click the key, high-light "Guest", Click remove, Click OK.

4. In some odd situations, you may need to check the registry to make sure restrictanonymous key is correctly set.

Click Start, click Run, type regedit, and then click OK.

Locate and then double-click the following registry subkey:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa

On the right side, double-click restrictanonymous.

Make sure that the value in the Value data box is set to 0, and then click OK.

Close Registry Editor.

Restart the computer.

5. If none of the above works, here is the ultimate solution from John Will.

Download the Windows Server 2003 Resource Kit Tools from microsoft Download center, which are a set of tools to help administrators streamline management tasks.

After installation is complete, click on: Start -> All Programs -> Windows Resource Kit Tools -> Command Shell

Then enter the following commands. (Attention: they are case sensitive.)

net user guest /active:yes
ntrights +r SeNetworkLogonRight -u Guest
ntrights -r SeDenyNetworkLogonRight -u Guest
The first command enables network access for Guest, the two subsequent ones change two different policies to allow network access for Guest.

So far, the errors should be clean and you should be able to double click into the computers on your local workgroup. However, nothing too interesting there except the default folder "Printers and Faxes". To enable file-sharing, we need to do a few tweeks, which will be discussed in my next post.

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How to set up windows home network

If you have more than 2 computers in your home, you may want to connect them together so that you can share files and resources among them.

There are two types of windows network you can set up -- domains and workgroup.

Windows domain is basically a server/client system, which is more secure and feature rich. How ever, you need a computer installed with Windows 2000 Server or Windows 2003 server as the dedicated domain server.

Comparably, setting up the peer to peer workgroup network is much easier on all versions of windows operation system, of course, it is not as secure.

To set up a workgroup in windows xp:

• Right click on the My Computer icon and choose PROPERTIES from the menu.

• Select the COMPUTER NAME tab

• Select the CHANGE button

• In the Workgroup text box, type a workgroup name of your choice and click OK. This workgroup name must be the SAME for all the computers in your Home Network. In the Computer name text box, type a unque name for this computer.

• Now Click OK.

• Click OK at the bottom of this window. When prompt for restart computer, Click OK.

• Repeat the above process for all the computers in your home, remember the workgroup name must be the SAME!

Now your workgroup-based home network have been setup. You can find your workgroup peers by clicking START -> My Network Places -> View Workgroup Computers.
If you click on the other computer in the Network it may only show you the SHARED FOLDERS that Windows sets up by default. To view other computers Folders and Files you must now share those items.

Better chances are you got error message such as "You might not have permission to use this network resource". Don't panic, we all got error messages. check my next post on how to trouble-shooting this.

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Adjust display settings to protect your eys

Feel your display uncomfortable for the eyes?

Sometimes it's because your monitor's brightness or contract were set too high. You can find several bottons on your monitor which allow you to adjust display settings.

If your monitor is CRT, try to change the refresh rate to the highest one.
For LCD monitor, refresh rates have no effect. To adjust refresh rate:
1. Right-click on a blank area of your desktop
2. Select Properties from the context menu
3. Select the settings tab
4. Press the Advanced button
5. Select the Monitor tab
6. Select highest refresh rate from the drop down box.
7. Click OK until the boxes are closed out

If you use winXP, you can re-rerender fonts to make them easier on the eyes by turning on "ClearType".
To turn on ClearType:
1. Right-click on a blank area of your desktop
2. Select Properties from the context menu
3. Select the Appearance tab
4. Press the Effects button
5. Select the check box before Use the following method to smooth edges of screen fonts
6. Select ClearType from the drop down box.
7. Click OK until the boxes are closed out

Turn you PC into HD TV with 20 bucks

Most cities in the US broadcast free TV over the air in HD (High Definition). To receive this signal an HD tuner is required. (Does this remind you of ancient radio broadcast? Yes, they are almost the same!) Televisions have an HD tuner built in. BUT, you can buy a usb plug-in TV tunner and enjoy free HDTV on your computer.

Step 1, Get a usb tv tunner with $15 to $50 bucks.
Search "usb tv tunner" on http://www.newegg.com/, I picked a cheap one, which works fine. Usb tv tunner is simply a usb adapter plus an antenna. The antenna receive microwave from air, usb adapter convert the microwave to digital signal your PC understand. Don't spend too much time on this, these products won't be too different. The only thing you need to worry about is the operation system the driver requires. Some driver only work on winxp and vista.


If you have hooked the usb tv tunner up, you may be enjoying many free HDTV channel on you PC right now. Depending on your city, you may have different channels available. The experience is similar to watching video on youtube, except the TV is really High Definition even with full screen. Also you don't need network connection, because signal is from your antenna which collect HDTV broadcast from air like radio does.

Step 2, Get a powerful antenna.
Want more channels? No problem, go ahead and buy a $100+ commercial antenna, or make a better antenna with less than 5 bucks and 30 minutes by yourself.
The link have detailed instructions. The key here is, HDTV is electromagnetic waves, to strengthen the signal, we need to form standing-wave in the antenna. Therefore, we need to pay attention to the wire's size, other things are just not so important details. Have fun and enjoy cool cyber stuff!

Cyber Jedi

Have you ever think of adding them together? Reverse Engineer hardware engineer Stanford CS107 computer scientist Fight Science martial artist 

DIY your wireless antena

Download antena template here

The idea is simple, microwave get reflected from the metal surface, thus condensed at a specific direction.