Maybe you don't have ownership for the folders where your data is, or the folders are read only?
If so, MC should place external tags anyway.
Google, take ownership windows 7, and you shall find a small register file to put it automatically in the windows register.
The result will be that a take ownership option will be in your right-click menu in windows explorer.
If you don't have enough experience with the windows register, ask somebody with knowledge to help you.
greets.