Problems after deinstallation of blender

Hi guys,

I’ve got a huge problem !!!

I’ve been working with blender on a foreign PC and after I had deinstalled blender all video and audio files couldn’t be played properly anymore. All the video files were bucking and the sound can’t be played properly, either.
They think that blender has deleted a windows file, too.
Is that possible ???
Did anybody else have such problems ???