[RESOLVED] Deleting Files and Folders

I have just installed a new WD IDE 500gb hard drive. I took my 120gb WD IDE hard drive and put it in a external HD case. Now what I want to do is delete everything off the external hard drive. I used Acronis to image everything to the new 500gb drive. So my original 120gb drive has everything on it. So it is already formated. I highlight everything on the drive and hit the delete key and it says Cannot Delete Administrator. Or I try to highlight some of the folders and it says Disk Not Ful or Write Protected.
How can I delete everything off of that drive so I can just use it to back up files etc.?
Thanks for your help.

Go to Disk Managment, select the 120 drive and format it. Everything will be gone and it will be formatted and ready to go.

Thanks for the reply. I formatted the drive and I am now good to go.
Thanks for your help.

You're welcome. Glad it worked for you.