How to clean invalid clipboard data

Sometime for unknown reason suddenly I'm not able to do paste operation. It happening anywhere, in explorer (file content) or in editor (image/text content). It seems clipboard contained invalid data or sort of. Now I have to find a way to clear this data, naturally by copy (overwrite) new data into, but it doesn't work! Copy and cut operation also failed.

If I recall Windows have a clipboard viewer program which filename was abbreviated and I can't find that one either (probably available in Windows 98 only). Eventually found "clip.exe" which control clipboard content via command line.

Then invoke this command (from CMD):
echo off|clip

Yay clipboard content cleaned up :). So while GUI applications failed to cure it, clip.exe come to save... weird eh?