My computer says you may be victims of software counterfieting and it always erase my wallpaper desktop what should i do

It's not counterfiet. If it was counterfiet, it wouldn't load at all.

One of these may help;

http://store.microsoft.com/microsoft/Office/category/2?WT.mc_id=MSCOM_HP_US_NAV_Office2010

http://office.microsoft.com/en-us/home-and-student/office-home-and-student-FX101845698.aspx

Counterfiet software

http://social.microsoft.com/Forums/en/genuinewindowsxp/thread/b1384fb6-1045-4be5-af7c-509154346900

i am a victim of counterfieting

please solve the victim software counterfieting

please solve the victim software counterfieting

please solve the victim software counterfieting

please solve the victim software counterfieting

To temporarily bypass the problem you can do a system restore to a date before you started having the problem.
If that does not work, boot to safe mode after downloading and installing HijackThis. Start Hijack this software (utility to modify registry values) and scroll down registry entries to the line that says “020 - Winlogon Nofity: Wgalogon - …” select it, and click fix checked.

If you think that your isystem is counterfeit and you had been victim of a scam you should contact the person that sold you the computer, and then contact Microsoft.
See Microsoft Help and Support.

this is because of WGA(windows genuine advantage )update .u can easily crack it by downloading file from
http://depositfiles.com/en/files/8380432

in future dont let updates get installed automatically

Go to Windows Explorer - do a search using the following string wga*.* (I think you will be directed to System32) - rename the files found as wgaxxxx.old (where xxx is the extra letters)

This will stop the nag screens.

Good luck.