Defragmenting C drive isn't working?

I wanted to defragment my C drive today, and i haven't done it before. I've only used the defragment feature for removable disks, and that usually works smoothly for me.

Then it said there were error and i needed to skandisk and repair problems, then try to defragment it again.

I used scandisk, and it restarted 10 times, said there were programs running that were writting on C drive and i needed to stop those programs. what programs? How would I go about stopping these programs for the time that i'm doing this? I didn't have any open windows, and everything was off my toolbar because explorer caused an error and shutdown when i was trying to defragment the first time. all i had on my toolbar was the time. what should i do now? i restarted and the computer is running the same as usual now, but i'd still like to clean up my C drive.

Defragmenting C drive isn't working?free adware remover

No problem about the typos. Everybody makes misteaks!

Obviously, you are using Windows 95, 98 or ME.

First, use Disk Cleanup to delete any and all unnecessary files. You might take this time to uninstall totally useless and unused programs.

Try to reboot into Safe Mode. This minimizes the activities, so that you can do a ScanDisk. Yes, it will restart many times, but picks up again where it left off, so eventually it will finish. It's just too bad that it makes you hit a button to get it to continue after every ten restart. This could take ALL DAY and Night.