Delete old system files?

[FordLord]

I have a hard drive that I use for storage that has files left over from a Windows 7 install that got a virus. Every time I try to change permissions, it won't let me. I have to change them individually for each file. How can I get rid of these files? They take up nearly 10Gb on my hard drive.

[editline]11:01PM[/editline]

I found out how to do it.
What I had to do was;
Right click ; properties ; Security ; Advanced ; Change permissions ; Click on my user ; Edit ; Check the top box for all ; Click OK ; Check both of the boxes on the bottom (Include inheritable permissions and replace all child object permissions) ; and Click apply.
After that I was able to delete the whole folder without any authorization windows.