The reason for this can be a multitude of issues – like a dodgy codec, etc – and seems to be rather in-discriminant as to which file type it decides to screw up with (AVI, MPG, WMV, ASF, etc).

To get around this problem though, it is possible to easily disable this feature. Either fire up a command prompt or execute this straight from the run dialog box:

regsvr32 /u shmedia.dll

And if you want to re-enable it again at a later date:

regsvr32 shmedia.dll

Now, the only knock-on effect is that you’ll no longer be able to see summary information in the file properties. In my opinion though, it’s a small price to pay!!