hi, ive reinstalled windows xp pro on my HD and it was running nicely. i installed all the macafee products- firewall, virus check and security. but i decided that the password ooption at startup from macafee security was not needed so i uninstalled this program. after rebooting the pc is very slow and when i try to open any media it says theres not enough memory. it also takes ageeees to boot up and shut down now. i get a blue startup screen from xp saying 'xp starting up'or something that i never got before. i have 512 memory in there, and 2 big HD's. please help! thanks. ps: how do i boot up in safe mode? can i undo recent changes this way?