Please help weird problem

Ok i just did a clean winxp pro install (like i have done many times now) i always format the drive first..

the problem is when i open certain programs they just close after a few seconds.. no message no nothing.. it just dissapears! im pretty sure it closes since it gets removed from the active processes list - ctrl alt del.

it first started when i installed norton antivirus 2004 trial, so i uninstalled it, and tried the 2003 version.. same problem.. i just thought ... it ill get another anti vir. but it also happens when i just run msconfig - "system configuration utility" and also regedit..

these are the only ones i have found that closes after about 4- 5 secs..

any help would be greatly appreciated!!

Cecilia