Josh Kaplan, president of Rescuecom said:
"From the calls we're getting, as well as our own experience in the past with all Microsoft's operating systems, we're recommending that people stick with their time-tested OS and wait for the dust to settle. There are some compelling reasons for both businesses and home users to move to Windows 7, so we're saying 'just wait for a bit.'"
I've already said several times: if you have Windows Vista there's little reason to upgrade your system to Windows 7. Even if you have Windows XP, there's little reason to upgrade, unless, as with me, you want to use the latest and greatest. In fact, the hassle isn't worth it.
On the other hand, if you do want to upgrade your system to Windows 7, don't bother with an in-place upgrade. In other words, do a clean install of the new OS. This is the same recommendation I made about Windows Vista vs. Windows XP, as well. A little trickery, BTW, and you can use an upgrade DVD to do a clean install of the OS, as well.
That's why I would not recommend upgrading an older machine. Doing a clean install means you have to reinstall all your programs. It also means that you'll have to back up --- and restore --- any data you want to keep. Of course, in a household like mine, most of that data is stored on network hard drives, not individual PCs, but that's not the case for most.
Microsoft also has to solve the aforementioned endless reboot problem with some PCs. There are quite a few people suffering the issue, posting on Microsoft's support sites.
While there hasn't been a solution offered by Microsoft yet, this sounds vaguely familiar. During the move to Windows Vista SP1, Microsoft warned that users who had certain driver versions could see ... endless reboots ... when trying to install Vista SP1, due to driver incompatibility.
Since these issues are only occurring with PCs that have tried to executte an in-place upgrade, it seems like a good theory to me. Of course, I could be completely off.
For now, if you want to try an in-place upgrade, make sure you image your hard drive using something like Acronis True Image. If the upgrade fails, it's easy to back out and return to your old OS by restoring your image.