Cant boot after reinstalling Office 2000

A friend had a problem with their computer and reinstalled windows 98 – the computer appeared to be working propoerly, but in the process, it looks like Office 2000 was wiped out. I tried reinstlaling it and when I restarted as part of the installprocess, I got a bunch of error messages that componenets were missing/etc, and when win 98 finally gets going, I get a fatal error in explorer and nothing is active and I can do nothing. Even rebooting in safe mode hangs the machine – where do I even start to get thigns back up and running?