With the introduction of the Active desktop it became possible to configure how folders should be displayed when using explorer.

Microsoft uses this feature to keep the clueless users to the beaten path, when they go exploring their harddrive using explorer. When trying to enter a Windows system folder one gets the following message:

Warning - Modifying the contents of this folder may cause your programs to stop working correctly.To view the contents of this folder, click Show Files

One can disable this warning by renaming the following file which resides inside the folder giving the warning:

folder.htt

More Info MS KB181689
More Info MS KB182000
More Info MS KB184785
More Info MS KB228035

Credits win98central.com