Receives message “this is taking longer than usual, do you want to close the project?” on Windows Live Movie Maker

Original Title: BATS

I  open a video from my camcorder in WLMM and it takes a while to download, showing a clock with the video greyed out.  Finally it is ready to edit.  It plays from the beginning with no problem, but when I move the bar along to another part of the film it stops working and I get a message saying "this is taking longer than usual, do you want to close the project?"  I say no as I have started editing, and after a long wait (up to 15 minutes) it starts again, I can make one edit and then it freezes again with the same message.  I have tried converting the video to a .wmv, MP4, MP3 using Prism File Converter, but the result is the same.  This makes editing virtually impossible.