You never want your *.mny file to be within "Program Files (x86)[\Microsoft Plus" folder.
The one thing you may need from that is the patched version of
"C:\Program Files\Microsoft Money Plus\MNYCoreFiles'mnyob99.dll"
That patch is also available elsewhere.
The others have told you how to find your *.mny file. But you might also want to copy over some of your recent *.mbf files to the new computer.
If your username is different on the new computer, you will need to change the backup setup. I would want to keep the username the same, myself.