wiping hardrive without os disk?

Hi im selling my now three year old pc but have hit a major and expected problem. When i got it it didnt come with an operating system disk (i have xp home) so now when i want to wipe it both for performance (as its got sooo slow and full of crap) and for data protection i cant just do a clean install.

Is there any way i can wipe it (so it performs like it did when i bought it) without getting rid of the os. Preferably if its software i dont want to pay much or anything if possible

I just dont want to sell what should be a perfectly good machine to some poor soul who finds out that it performs like a pentium 3 800mhz .

thanks in advance

patrick

I tried that and it still is really laggy just on basic apps and it just feels really bloated. Like its eaten too much

Is there a way of literally wiping everything (like a clean install) expcept for xp.

Or if that isnt possible could i make a personal copy of xp from my computer (how would i do that) then do a fresh install? Obviously for my personal use only

thanks

patrick

ok so it ought to once i have unistalled everything be as fast as when i bought it. For instance since buying boot time has skyrocketed.

thanks

Nah i think i know! Anyway ill post back when ive done it... thanks for the help m8