i recently was downloadidng some movies when it kept aborting them then a window open saying fatal internal error please donwload limewire so idid then donwloaded java again and it keeps on happening

Go to Add/Remove control panel & remove Java. Then install only the "Offline" version from here Java 1.5 (take the JRE)

Also delete your LW preferences folder whilst LW is closed as decribed here Point #2 & 3 in Fixes for Limewire (sample image included.)

will this erase all the files i have like my movies

No, not unless you download your files into your program folder. Which is a silly place to have a downld folder. Normally your downld folder is here: C:\Documents and Settings\"your account name"\Shared

Whereas your LW program folder should be around here: C:\Program files\LimeWire

Oh upon re-reading, you're not reinstalling LW anyway. So the answer is no it won't affect your downld files.