it's not the primary partition i can't access. Windows boots fine, but when i try to access the D: partition, it says that it's corrupted. When booting up the PC, it tries to check that partition, but then it says that the Master file table is corrupted. Nothing he can do about it, skips the chkdsk and continues to boot.
There is no different windows installation on the drive, there's only one. Fresh copy was installed over the old one.