What a waste. The Windows Media Player provides most of the software you need for playing multimedia files. Unless you have a specific reason to keep it delete any other software that is used for playing these files. Serious space hogs and while some are very handy they are always on the installation disks or CD if you really need them, so banish them. Powerpoint is the big offender here.
TXT files are everywhere.
Scan your root directory and your Windows directory. These are created if you are FTPing files and are useless. They get created when you install the software, and mark directories created by that software, and then hand around doing nothing particularly useful so why not get rid of them. You will be amazed at how many turn up. Check for anything interesting and then delete whatever is left over.