Can't startup computer !

Usually attributed to a dead battery. You might try restoring the BIOS to default, you'll need to look at the motherboard specs and find the two pins to short out. How old is the PC?

look what my problem was about and maybe u can find something usefull:

i inserted a pc game disk on the computer that didnt work,actually before restarting it,and it couldn`t acces anything(there was a small line that was appearing and disappearing all the time)
than i remembered what i did before and imeddietaly took the cd out!
than it worked like before, it was so redicioulus!#!#!

so now i am gonna telling you some tipps if u didnt have the same problem:
if you can acces F8, and go one "safe mode" and if it would really work so the problem is fixed,
u now just have to go on the run meny
type "restore"
and make a backup now.

dont use the "restore the computer to the last known good config" meny
i always used it an it never worked
that is one of the useless aplications on windows.

and if nothing works go one the bios
(press del to run setup)
there u can install a new fresh windows but everything on you`re drive C: is gonna being deleted,things on the desktop,on mydocuments(everything)
but u can also use it on the normal way
just insert the disk and wait if u can acces the setup
there you can formate it without deleting anything
really i dont now why but everytime i use it
nothing is gonna being deleted.

please if something on this was usefull
please let me know
best wishes g.berisha