Nadhani kuna kitu haujatuambia. Software imekataa kuinstall kwa vile sio compatible lakini imeharibu boot process? Highly unlikely.
Anyway weka CD ya windows kwenye machine, restart, boot from CD; kufanyikisha hili inaweza ikakubidi uchague CD kama boot device au uingie BIOS setup na kuchagua CD kama boot device ya kwanza.
Then ukiboot from cd itakwambia uchague lugha na keyboard, chagua then nenda next, utaona option ya Repair, chagua hiyo kisha fanya startup repair.