Hi Asadullah,
Get rid of Spyware Nuker and Spykill because they are unproven and/or rogue spyware applications as Spiritsongs said.
http://www.spywarewarrior.com/rogue_anti-spyware.htm
Download install and update the excellent and free Ad-Aware and Spybot Search & Destroy:
http://www.lavasoftusa.com/software/adaware/
http://www.safer-networking.org/
Update Ewido.
Download F-Secure BlackLight:
http://www.f-secure.com/blacklight
Download a good free firewall like Zone Alarm if you haven’t got one already.
Disconnect your internet connection.
The key for the free version of avast! only requires registration. In the meantime, run a boot time scan with avast! (Schedule boot time scan.)
Run a scan with BlackLight.
Restart you computer in safe mode and run scans with Ewido, Spybot and Ad-Aware.
Repeat the scans until nothing new is detected.
Install your firewall, reconnect to the internet and only allow trusted programs to connect out.
Report any symptoms, detections etc you still have.
Good luck!
