Data Execution Prevention

[Guest]

While beginning a defrag on volume C: the process was disconnected when
trying to move a file. I tried several times to restart-when prompted, but
after the 3rd or 4th the DEP shut down the defragmenter NTFS module. I just
downloaded a security program from AOL, (McAfee) and as it was free I'm sure
it's not the best but I just got this PC online after 6 mo. and my old
security software was expired...well, it's a long story but living overseas
now has complicated things. So, firewall-ok, antivirus-running, all in the
green. What do I do to get this thing defragged??
PS: Before trying to defrag I cleaned out many infected files, two of which
were not able to be deleted. Please help!

 

[Guest]

DEP isn't part of the antivirus, it's a system add-on supplied by Service
Pack 2.
You find it in the System Control Panel. You can set an exception for
defrag, or turn it off altogether.

DEP should in theory provide some protection against certain types of
exploit, but exactly how much protection isn't clear. Some people reckon that
compressed executables aren't protected anyway, so it's of little value as
the malware-coder only has to use a 'packer' to get round it.

If you haven't removed the infection fully I'd look to that first anyway.
Have you tried deleting the files in Safe Mode?