DO NOT REMOVE user32.dll, even though AVG 8 states that there is a virus in the file.

Doing so will remove the file, and cause a BSOD, and makes your system unable to boot.

It marks the file as infected with Trojan Horse PSW.BANKER4.APSA.

Possibilities are to wait for an update from AVG, or (preferably) upgrade to XP SP3!