In theory, the easiest way to do something like this is to backup a couple of files from the Windows folder, then reinstall, then restore those files. In theory being the important part. The reality is that there are so many things that can change that will ‘void’ the WPA information that this isn’t a practical solution for a complete reinstall.

The ‘safest’ way to accomplish something like this is to save a copy of the disk image, which would include virutally all the same information used to originally activate Windows. There are a number of programs that do this, some free, most not. The free ones have typically been based on GNU/Linux or BSD Unix, but I came across a cool free program the other day that will do this in Windows!

DriveImage XML (available here) is a free program released by Runtime Software. It allows you to build an image of a hard drive, even one in use, which can be later used to restore the drive to the exact state of when the image was created.

Here’s what I did. First, I backed up whatever was important enough to save. (You will be reformatting your hard drive, so don’t skip this or you’ll be sorry!) Second, I installed Windows XP Home Edition on my notebook from the original CD. Third, I called in and reactivated my installation. Fourth, I installed all necessary drivers and all updated software and fixes from Windows Update. Fifth, I installed DriveImage XML (but no other software; at this point the only things installed on this computer were the operating system, updates from microsoft, drivers, and DriveImage XML).

At this point I discovered that I had 7 gigabytes used, which seemed high to me. After a little investigation, I discovered about half my used space was due to System Restore having created restore points during the update process. After deleting those, I was down to about 3.5 gigabytes, which seemed more reasonable (though still larger than absolutely necessary; Microsoft is not known for their leanness).

After running DriveImage XML, I was able to create a drive image that was about 1.8 gigabytes after compression. I created a bootable ISO image with PE Builder (another freebie – more about that later) that included DriveImage XML and the hard drive image. I then burned that ISO image to my DVD writer with Nero. Finally, I removed the DVD+R disc from my desktop and used it to boot my notebook and restore the drive image. Voila!

Note that I did have a couple of problems with the DVD, but I don’t think they were related to DriveImage XML, PE Builder, or Nero. It took a total of 3 attempts to successfully boot the DVD+R, but once it booted, it worked flawlessly.

Oh, and in addition to backup and restore, DriveImage XML can perform Drive to Drive copies, and it can open an archive and allow individual files and/or folders to be extracted instead of restoring everything first.

If you are interested in saving images of hard drives for archival purposes, take a look at DriveImage XML. I think you’ll like it.

Reason 2: Multimedia timers are a way to get relatively high precision timing for events. I need to use them for animation in a program I’m working on for both Windows XP as well as Windows 98. I took my program to a Windows 98 machine to test it, and kept getting garbage back from the API. I assumed I was doing something wrong for a couple of hours. Finally it dawned on me to reboot the machine, and suddenly, it started working correctly.

Reason 3: The documentation in the platform SDK lies. Ok, I’ve known that for a long time, but it bit me today. One of the RAS structures is documented to have a certain number of fields when used with Windows XP. It doesn’t. The documentation is not the same as the structure as described in the platform SDK header files. {sigh}