When my computer is booting up and it passes the xp logo sceen with the loading bar, it seems like the system sort of hangs before loading into windows. Following the loading screen te screen remains black, I can hear the computer doing somehting but it remains black for about 20 seconds or so thenactuallyy starts up windows. Once windows does finally start everything loads a lot slower than it should and I it's a 3 ghz. computer...any idea what's going on??

Normally a sign that you have some driver that is odd or wrong. Start with Event viewer logs. If it did work correctly then consider a restore point to that time. I read it wrong and answer it wrong too. So get off my case you goober.

Run Chkdsk. 1: Open My Computer, and then select the local disk you want to check. 2: On the File menu, click Properties. 3: On the Tools tab, under Error-checking, click Check Now. Tick both boxes, all files must be closed for this process to run. If the volume is currently in use, a message box will appear prompting you to indicate whether or not you want to reschedule the disk checking for the next time you restart your system. Then, the next time you restart your system, disk checking will run. Your volume will not be available to perform other tasks while this process is running. If your volume is formatted as NTFS, Windows automatically logs all file transactions, replaces bad clusters, and stores copies of key information for all files on the NTFS volume. Reboot.