Well its obvious why you are having problems. Stopping a disk check "unexpectedly" is almost a guarenteed way of fudging your computer.
When your computer starts, go into Setup (I think its ESC or F1/2) and do a system restore. You will lose your files and crap but if you are patcient and can transfer them to a disk/drive first, you will be fine.
Once again, you need patience. You can do system restore through regular windows (control panel) to a time before you started the disk check, but even that may not work because the files will be corrupt during the restore.
When my HD went the other week, I couldnt do a restore (
any restore) because some files were corrupt/missing. You may get that problem.
In future, don't shut it down during a disk check/defrag, you are bound to have problems.