Windows XP strange behavour. Need help...

[ibro]

1. I launch WINnerTweakXP SE and it try to install other
programs, not windows components.
When finally I cancel these installations the WINnerTweakXP is launched?

2. I tray to install another program but windows display a mess box that the file
is not found, although the file exists on HD and I can open it in explorer?

Scannig for viruses and trojans show me that the system is not infected.

I think in the wndows registry something is wrong, but what?

Thanks.