Cannot change vm's partition size

I accepted the default partition size for my XP machine, but I need it smaller. I have half a terabyte available, but the XP now only uses the default 65 gig. Parallels doesn't do that, but the help docs told me to download Acronis. I tried to do that, but it doesn't work.

I had delays getting all this started and my 30 days free support vanished.

Help!!

Dave Hay