Hi. If you're still using IE7, you're probably running a severely out of date, and vulnerable system.
Updating to IE9 is fine, and won't affect your full E drive, but leave that for a bit.
First, make sure you have a recent backup of anything you wouldn't want to lose.
Then, make sure your anti-virus is up to date. Then run and rerun and rerun Windows update, until it tells you there are no more updates. Then rerun it once more, to be sure. In the windows update screen, be sure your "important updates" are set to run automatically.
If you have Flash installed, or Adobe reader, make sure you have the latest versions.
Same goes for Java, except that you might consider simply uninstalling it instead. Whichever, just please don't run your system on the internet with outdated software.
After making your updates, re-post, regarding your full E drive.