need help i screwed up my bosses toshiba satelite p305d

help toshiba satelite p305d had windows 7 double installed at idle it was running at 70 % of 3 gigs of memory being used with only os installed (just installed an hour before running totally bare no programs installed not linked internet yet no pics nothing ) so he asked me if i thought i could fix it. i said yes(and im not stupid ive never came across a problem that i could not solve easily and quickly and ive done this stuff a hundred times before. but ???)

i shredded the hard drive with a PROGRAM tried to install a type of xp sp2 started great during install laptop just cut out. so I tried again and again..... then i tried xp sp3. still cut out during install after i chose drive and clicked install but at different places of install so its not my copies of xp. but after that i used a program to reset cmos but hit wrong button and wiped cmos now it powers and immediatly off and cycles on off on off indefinately help help help !!! i dont know how to fix this help im screwed if i cant fix this by morning please help me im mad irritated and not stopping until i get it im doing 4 thing at once thats why my spelling and grammer is horrid @ THE MOMENT and the long ramble