I've been searching the whole internet for solutions on solving my problem on the instant slowdown i started experiencing when I start up my computer. Usually it takes the Windows XP load screen around 4 ticks for it to load the profile screen, presently it takes around 10. I'm pretty pissed since I don't want to reformat my computer.

Anyway, the things I tried to speedup the load time:

Removed all unnecessary software
Fixed registry with Registry Mechanic
Removed useless startup programs
Ran anti-virus and anti-spyware and removed all of that
Defragmented hard drives

But no dice, is reformatting really the only solution? Please reply asap! Thanks!

Could try a Windows repair off the CD

If I repair windows from the CD while XP Sp 2 is installed, what will happen then?

A repair resets Windows to a more basic state, e.g., you'll have to reinstall the drivers, but doesn't wipe everything out like a clean install, i.e., you don't have to reinstall programs or worry about losing data, although it's always a good idea to back up your data, but then this is always a good idea even when things are running smoothly. I'm sure someone can give you a more detailed, technical explanation of precisely what it does. But it does often fix Windows when it gets corrupted. Of course you have to have a Windows CD to do this, i.e., if you bought an off the shelf computer that just came with a recovery disk, frequently you can't just do a repair.