hard disks problems

i cant dx or repair my hard drive... i get err message....disk dr. cant get physical characteristics and is unable to test partition info on drive. it also says operating system or another process has exclusive access to this drive, or some of its files....cannot continue with repair under these conditions...
i also noticed that my hard drive c does not have a volume label. Can anyone tell me whats going on?
it seems my system is running slower then it should
Help!

 

What OS are you using? In XP I know you need to set the HD to run a scan before next startup. Defrag should work no matter if your in your OS or not. In earlier editions you should be able to start in safe or dos mode and then try running it. Make a windows startup disk and see if that works.