I recently added new functionality to my Hex Editor: the ability to view and modify physical memory addresses.
I have only tested this feature in Windows XP, and I would like your help to see if it works on other operating systems (NT/2K/2003)
If you open physical memory in non-readonly mode you have to be careful. Not only can you crash your computer, but it is possible to modify your BIOS and render your computer unuseable.
It is a very tedious process to open memory in non-readonly mode, though (even administrators cannot normally do this) so you can feel safe.
HyperEdit is available at http://www.strandmark.com/hyperedit.shtml