
disable flash in win XP -- with out any popups, error messages, or prompts.
add this key to the registry
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\ActiveX Compatibility\{D27CDB6E-AE6D-11CF-96B8-444553540000}
add/create a DWORD value inside this key called "Compatibility Flags"
Set Value Data to 400 and Base to Hexadecimal.
To enable flash again simply delete, or rename the key.