I updated from WinXP SP2 to SP3 and PM7 went a bit funny - noticeably with Type1 fonts, but it was already installed. I don't have 100% confidence in it.
But I'd not recommend PM7 - install the InDesign trial which will convert/open PM7 files, usually OK subject to fonts and images being available.
Iechyd da! John
20:50 BST 31/07/2009
Europe, Middle East and Africa