Cannot delete files from Acomdata 160 hd

what is the error message you are getting? what OS are you using?

What type of files are you trying to delete?

I will assume the most popular answers.
If you are running windows and trying to delete files and getting the error that the file is a system file or in use and cannot be deleted, then you need to get a utility called move on boot...it will move or delete files when you are rebooting your computer, before they are in use.
You can find move on Boot by google search and many other free utilities that do the same thing.
I would make sure these files aren't needed as yo could kill windows easily.

Virus and spyware removal often requires this sort of removal.

Hope that helps,

Flyback