Since you don't want the technical details I'll just give links about that but the issue is well known in support and Microsoft circles. Microsoft has not addressed this yet but here's the cause. A corrupt (according to Microsoft's terms) JPEG, image, AVI or such files will cause Explorer to crash and exit.

There is no fix today only workarounds from moving the file (technically hard for those that don't want to get technical) to other deeper technical solutions.

We all wish Microsoft would fix that.
Bob

More at http://forums.cnet.com/5238-7813-0.html?kw=Explorer+closes