All the files placed in the "Content.IE5 folder are stored there by Internet Explorer so the next time you visit a web page the page will load quicker. They can ALL be deleted if you choose. Normally, there is one "hidden" file in "Content.IE5" folder which can't be easily deleted and it's called the "index.dat" file. It also "stores" information about pages that were visited but it's locked by Windows and must be deleted from a command prompt or from Safe Mode. But after deleting it, a new one will automatically replace it.

In regards to WHERE infected files might reside...
ALMOST ANYWHERE...and...There are LOTS OF TIMES when an antivirus program can't delete a file.

Many trojans and some viruses are "locked" by Windows in a few different locations. They can be in the "System Restore" volumes on Windows ME or XP but files in this location can be removed by temporarily disabling System Restore. In addition, on ANY Windows operating system, infected files might reside in the C\Windows\System32 folder which prevent them from being easily deleted because they are being "used" by Windows during normal operations. In order to delete files of these types, a number of different methods might be necessary. Sometimes, booting into Safe Mode will free them up. Sometimes, a registry entry needs to be removed first or the "service" which is running them needs to be stopped first, then they can be deleted. Sometimes, deleting from a command line will do it. And sometimes, third party programs, such as "MoveOnBoot" are required..

It can become a long process to find and delete some types of malware, but it is necessary to allow your computer to "be all it can be".

HOpe this helps.

Grif