Babarali --
Since the behavior does not replicate its self in *Safe Mode* I would say you have something (service or application) running in the background.
You may have a virus or some malicious code running.
Install MSConfig from a XP box and set it to *diagnostic* then reboot.
This should place you in *Normal Mode* and allow you to better trouble shoot it, use MSConfig to see what appz are running, check Task Manager and you registry, you could also check the registry first, in safe mode.
If you need a copy of MSConfig, check here:
ftp://ftp.idahojack.com/Files/software/msconfig_for_2k/
Once up and running in normal mode use *Ad Aware* to scan your system.
You can obtain a free copy from there website at:
www.lavasoftusa.com/support/download/
Good Luck,
