I too, started having this problem after installing H&R Block At Home Premi
um & Business and trying to print my tax return to PDF format.
The first time it happened, I chose "Yes" for the prompt about reinstalling Adobe resource files, and it rebooted, and then the system bug-checked with a BSOD, and got stuck in and endless cycle of rebooting until I inserted my Norton Ghost image boot CD and restored to a back up image. Very serious system corruption. I don't know whether it's H&R Block's fault or Adobe Acrobat.