HELP BIOS BLACKS OUT

hy, im new here so dont know if this is the right place for this SOS.

few days ago i wanted to format my comp and xp it, i got this non orig XP ofcourse from my friend and when i installed it and tried to log in i had some auto restarts before i got in .. so after i restarted my comp (after installing few progs), i got this cmos error line but if i pressed F1 i could go further ..
anyways i got much trouble whit this xp and i tried new xp cd what i got now .. but windows in my comp dont see it .. nice .. but my laptop sees it clearly and fine - even plays the autoplay correcty , so i tried in BIOS to change the setting so that it reads CD first so i could xp my comp again whit new one , but when i exit BIOS and press F10 when it should restart my comp , i does nothing and keeps the screen black .. i turned my comp off for 10 minutes .. tried again .. nothing .. then i read something that removing the battery from motherboard for 30minutes it defaults the BIOS .. so i did and tried again .. the minute i tried to save the BIOS settings , i got this black screen again ... dont know what to do now . wanted format the comp and xp it , but seems now like i formatted it for good :) ..
if anyone know some tips tricks how i could fix this without buing new mb or comp totally , then id be VERY thankful ..
sorry my english , im estonian ..