Gets to Login Screen but after login it slows down... a lot!

I'm using Win XP sp2 and I usually leave my computer on 24/7. This morning I tried to open a file but it never opened. I went into the task manager to see if its even processing and it was there but the ccapp was taking all the cpu. So i tried to shutdown and restart. After that windows boots up to the login screen just fine but when i click on my account it take a long time to show my wallpaper. I can pull up task manager and the cpu isnt being used. the hdd is only accessed in little bursts. After a while the start menu pops up. any keyboard commands like to bring up win explorer takes a long time and all the commands pop up in a big burp of of command executions. I'm trying to reach system restore but cant. I'm not sure how to get into safemode with this system because just after post when f8 is usually used to bring up the menu the system opens a boot drive selection screen. During the RAM tests during post theres text stating press del to enter bios and f8 to enter boot drive selection so im not sure how to get to safemode now.

Well, I was finally able to get into windows. I had to get to get to a command prompt and I ran chkdsk. Even though I was able to get logged in my processes showed the User Name in the Processes tab of the Task Manager as blank. I just ran a restore to 3 days ago and everything is working now!