I have had a scan running for about 7 hrs and it is still only at 57% complete I heve never experianced one this long before also noticed that it is slowing down the PC (for the last few scans)
If you have very large drives or if a drive is compressed or encrypted, or if you have a huge number of zipped files, then the software will take a long time to scan. Is this a scheduled scan or a custom one? With the latter you can perhaps tailor the scan to be more selective and take less time as a result.
When posting back give details of the version of McAfee (from "About") and what operating system and service pack this is.
That said I have 3 TB's in total and a full scan of everything takes about 2 hours.
Technical Support may be helpful here and Australia is the one for your area. http://service.mcafee.com/TechSupportHome.aspx?lc=3081&sg=TS
It's free of charge.
What operating system and service pack (if applicable)?
Drives that small shouldn't be an issue.
You need to do a chkdsk /r to check for and correct any disk-read errors.
I can post a guide to that if I know what OS this is.
Did you run the disk checks with the /r parameter? That one not only detects errors but tries to repair them.
If you did and it turned up clean then I suggest contacting Technical Support via the link under Useful Links at the top of this page.