In windows XP, you can change the windows default identity (Computer Manufacturer Logo and other information's) and share your own private identity there. First you right click on My Computer then click on Properties, here may be you will see computer manufacture logo or empty area. So add your own logo there to make your computer more private.

Follow the given steps to change the system default Properties identity:

First click on Start button and type notepad in Run option then press Enter.

Now type the following text in notepad. 

[General]
Manufacturer="
www.ComputerFreeTips.com"
Model="
Computer Free Tips and Tricks!"
[Support Information]
Line1="We offer various help topics including A to Z Computer Free Tips and Help."
Line2="Visit daily for new tips
www.ComputerFreeTips.com"

There are some standard keywords, for example Manufacturer, Model, Line 1, Line 2; you can not change these keywords. Now save this notepad file in c:/windows/system32 folder with file name, OEMINFO.INI.

Now choose your favorite picture to set as logo, using any picture editor resize the picture size approx. 150X150 pixels then save it in c:/windows/system32 folder with file name OEMLOGO.BMP.

Now close the all files and restart your computer after any changes to go into effect. To verify these changes, right click on My Computer and open Properties.

Under General tab, verify the system properties with new settings.

Now click on Support Information for more detail.