ms config is your best bet, it should speed it up no end. all those programs are eating in to your cpu and ram power. after that is should be fine.

if you wanna run a complete format, which is advisable now and again, cus adding and removing programs, deleteing virus and stuff can alter the registy

boot up your computer and right asit turns on it should flag up a key to press to run the BIOS, go into this, then in on of the menus there will be a section that says boot, this should have your hdd selected as it will boot windows form the hdd. select this and change it to cd rom

then exit and save your changes

put ni the os disc and fire up your computer, usually they say press f8 to boot from disc, do this and it will load up from the disc and reformat windows.

peace
snowblind