This is another reason I don't like Windows.
A neighbor has been away for a couple of months. When they came back he started updating his software. He was in the middle of updating Adobe when the install crashed. When his PC rebooted it told him that NDIS2SUP.VXD was missing. This was a result of updating the PDF viewer! What does this have to do with a PDF file? That and the update also made a royal mess out of his hard drive and registry file. There were crosslinked files all over and the chkdsk on startup would not fix the problem, it told you that you had to use the windows version. That is a problem in that his system would not boot to Windows even in safe mode. A simple update totally screwed up the registry and HD. Later he will have to rebuild his machine from scratch. I have stopped counting how many times he has had to rebuild the machine because the registry is screwed up by a simple update to his software.
We were able to do backups of his data thanks to the Knoppix CD that I had. As he has a router he has access to the web and can pick up his email via the webmail interface that his ISP provides. He is still unsure about having Linux as his full time option, but, he appreciates having the CD in an emergency so he can at least send/receive email.
Update 2005/07/27 -
We were able to get things back up by deleting his network card and then let the system detect that there was 'new' hardware. It seems to work, but, you should not have to do that when you are updating software that has nothing to do with networking.