There may be an issue with Emacs 22.1 for Windows and antivirus program that is not covered in the FAQ and that I have not found discussed.
I witnessed a laptop becoming unresponsive when running Emacs from a DVD, I have seen Emacs running from DVD freeze when left open and unused for some time an a lab PC, and a user has reported that his laptop became 'very slow' after unpacking emacs onto his hard drive and that he was later told he had a 'trojan that was bringing in friend viruses.' Recently I was at a PC using Emacs that I had just downloaded when the PC became unresponsive. Dropping into Task Manager, I found that McShield.exe and VsTskMgr.exe were alternating taking full system resources until I removed Emacs. These are components of McAfee VirusScan. This last experience makes me suspect there may have been something to the earlier reports and experiences related to an interaction between virus scanners and Emacs. I do not own a PC and have no experience with virus scanners, so advice on this would be welcome. In particular, confirming if there is such a problem and, if so, advice on how a user with a portable version of Emacs might avoid hangs when going to a new PC would be greatly appreciated.