Strange Windows Mediaplayer 11-problem in Winxp

when viewing mp4-videofiles in administrator-account i see an english version of WMP11.
Now as a news in restricted account some mp4-files are associated to irfanview and are working there.
files in other directory are associated to WMP and give a warning i must first deinstall this english version(or when i try to install german version)
but i cant find WMP11 english-version.
What i see on programs-folder are multipe files incl. migrate.exe and setup_wm.exe. dont see the program neighter in software nor revo uninstaller.
maybe i had to remove WMP once when there was an association-problem which we discussed already.
how to deinstall WMP since i cannot associate the files in restricted acount only when finding the program hopefully. then i will leave english-version alone. thanks a lot.