Yes, the Recovery console/Command Console is a useful tool. It has saved me from reinstalling Windows 2000 twice. But it is inferior to, say, a Linux rescue disk, since you cannot edit the registry, where all the important settings are stored. The enable/disable commands allow you to change a very small portion of these settings, but it is not always enough.
This actually happened to me a few weeks ago. I changed keyboard drivers for my new Microsoft Natural Keyboard Pro, and I (ahem) chose the wrong driver, even though Windows warned me that it might not be compatible. My keyboard uses the PS/2 port and the driver I chose apparently was for an USB keyboard. The driver change disabled the i8042prt driver for the PS/2 ports. Result: Both the keyboard and the mouse stopped working after a reboot.
Good question by JayBounci:
There were a few other ways you could have done that (last known good configuration, and safe mode, which would have given you the most default drivers possible). Why did you use command cons for that?
Answer: Safe mode didn't work because the keyboard drivers need to be loaded even in Safe mode. Last known good configuration didn't work either, but that is probably my fault. I tried the recovery console before remembering to try LKG.
Using the recovery console I could disable the kbdhid driver and reenable the i8042prt driver, but it still didn't work because a setting in the registry told Windows that the driver for the keyboard is kbdhid. The mouse still refused to work too. I guess that the kbdhid driver was being loaded by Windows even though I had disabled it, and that it prevented the i8042prt driver from loading.
Solution: I installed another copy of Windows on a spare partition, started regedt32 (not regedit), mounted the c:\winnt\system32\config\system registry hive from the broken installation and changed the driver for the keyboard. Problem solved.
By the way, the keyboard settings is in the following key on my computer, with a PS/2 keyboard:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\ACPI\PNP0303\4&244b3c61&0
String value: Service=i8042prt
You need to change the permissions of a few of the parent keys before you can change the Service value.
You may ask why I did not choose the Repair features of the Windows 2000 setup. Answer: It may work, but it changes a lot of registry settings back to the factory default, and you will need to reinstall the service pack(s), the High encryption pack etc.
Good question by JayBounci:
There were a few other ways you could have done that (last known good configuration, and safe mode, which would have given you the most default drivers possible). Why did you use command cons for that?
Answer: Safe mode didn't work because the keyboard drivers need to be loaded even in Safe mode. Last known good configuration didn't work either, but that is probably my fault. I tried the recovery console before remembering to try LKG.