Receipt archiving mistake

I made a mistake that I'm writing up here in hopes of helping you avoid it. I like to keep a copy of receipts that I received electronically, in electronic form. At first I would just take screenshots of the confirmation page on Amazon for example, and then paste into Paint and save as a jpeg. Then I found Microsoft had created electronic printer driver formats, MDI in office and XPS in IE. So I could "print" the receipt to a file. What I really wanted was to save to PDF, because I was concerned that my information might outlive the program that it was stuck in. But Microsoft PDF support is still lacking, though they have made some progress in Ms Office.

So I have all these pages in MDI format. It turns out that even Microsoft Word can't read MDI. Nothing can besides the Windows scanner viewer. Due to other circumstances I have finally realized I need the broad support of PDF. It helps to know it's an open standard, not owned by Adobe. I had used a "print-to-pdf" program years ago that had "ghost" in the name, that had not been very dependable. But I steeled myself and began a search for a PDF printer driver. It turns out there are actually quite a few free ones available now, that get very good reviews. In the end I went with a recommendation ( http://lifehacker.com/software/pdf/download-of-the-day-pdfcreator-windows-251080.php ) from LifeHacker, because I always worry about spyware in shareware. PDF Creator is actually open source, so that is even better. 

The part I like is that turn-about is fair play.. I can open my MDI docs in the Windows scanner viewer, and choose print to pdf from there, and convert all those MDI's to PDFs.