What Microsoft Says
Microsoft's Knowledge Base revealed that the problem was known
and documented. It was covered in Knowledge
Base Article 822430.
According to Microsoft, here are the symptoms of this bug :-
When you click a large Audio Video Interleaved (AVI)
file in Windows Explorer, Microsoft Windows may stop
responding (hang). Additionally, when you view the Processes
tab in Windows Task Manager, you notice that the Explorer.exe
process consumes 100 percent of CPU usage for up to two hours
or more.
And the cause :-
This problem occurs because Windows scans the large
AVI file when you click it in Windows Explorer. When you click
a large AVI file (for example, when you click a 700-megabyte
[MB] AVI file) in Windows Explorer, Windows tries to query the
index of the file. If there is no index information in the
file, Windows performs a loop to check all portions of the
file to build the index. Because of the large size of the AVI
file (in this example, 700 MB), it takes a long time for
Windows to scan the whole file. Because of this behavior, the
CPU usage of the Explorer.exe process reaches 100
percent.
The bug is confined to Windows XP Home,
Professional and 64-bit Edition. Hooray... I
suppose.
The good news is Microsoft has a hotfix for this bug. The bad
news is they require you to call them up for the hotfix! 
So, what do we do now? 
Searching For A Fix
I don't know why Microsoft has to make us jump through hoops just
to get a lousy hotfix for a very irritating bug. But I sure wasn't
going to waste my time and money trying to convince them on the
phone that I needed the hotfix.
So, I did the next best thing - I googled! 
Surprisingly, it was slim pickings at best. Most of the pages
pointed back to the Microsoft Knowledge Base Article 822430. But I
did eventually find a solution!
The Solution
For the record, I found the solution in the Tech Support Guy
forums. Specifically, it was this page - Deleting a file (XP).
According to LwdSquashman, this problem can be easily
solved by a little registry editing. Here is his solution :-
1. Open up regedit.exe.
2. Go to
HKEY_CLASSES_ROOT\SystemFileAssociations\.avi\shellex\PropertyHandler
3. Delete the "Default" value which should be
"{87D62D94-71B3-4b9a-9489-5FE6850DC73E}"
That's it! It is so simple. I tried it out myself and it worked
like a charm!
If you are facing this problem yourself, try this solution
out!
Questions & Comments
If you have any questions or comments about this article, please
feel free to post them here!
We look forward to hearing from you! :)