My LapTop Xp go crazy

[Slydragon]

I recently uninstalled McAffee from my laptop since I am going back to Norton. Now my laptop runs slow, loads up in 10 minutes, and some programs don't run until I restart the computer then they start up, but can't execute because the computer is shutting down. I plan to re-install XP, but I sense that will not fix the problem. XP has been good to me, but I may go back to NT or 2000 if these problems continue (is that possible to do that on a laptop that came with XP?)

Also, I am unable to un-install Mcafee Virus Scan and Security center. They seem to hide somewhere in the registry and never execute.

Any ideas, please email me ASAP or before Thursday
slydragon@yahoo.com
Nick