repairing windows?

> Ok here is the lowdown, bought a new processor (p42.6),
> motherboard (Asrock)and 512Mb of DDR ram all compatible.
>
> Hooked all this up to an existing machine which is running
> windows 2000, two hard disks, 1 CDRW, Geforce 4 in AGP
> slot and Network card
> in one PCI slot.
>
> Seemed to work but started getting blue screen of death on
> every boot asking to do a chkdsk /f.
>
> So I started windows in safe mode and command prompt. It
> takes ages(3-4 min) to get to and when i tell it to run
> chkdsk on both hard disks it says it will do it on next
> startup. Yet it doesn't, it just goes back to blue screen
> of death on startup.
>
> One last thing, it asks when chkdsk on one disk if it
> should force a dismount. Will this damage anything at all
> by forcing it?
>
> Also is there any way to replace files that may be missing
> with windows? Any help most appreciated.
>