I have AA9 and Win7 with no problem. Does he have the problem from other programs? I suspect he had a default printer set to print to file. At least that is where I would be looking. However, if it happens with all printers, that is a different issue. Such settings generally come from the OS, not from Acrobat. Acrobat simply loads the printer selections into memory.
At this point I would recommend a repair (Help>Repair in Acrobat) and then an update. I suspect he may be running AA9.0, not AA9.5.3 or such that is the current version. The updates have to generally be run in order unless different information is provided. Most of them are not cummulative. If possible, try to run the updates from Help>Updates. I have typically found that you only have to reboot after the last update is complete. However, if there is any concern, try the reboot whenever asked.
