Enlarged text after booting Windows 98

I have a computer that is unusable because the display is messed up. During booting, the background shows up normally. Once the system is booted up though, it’s like I’m looking at one little corner of the display blown up over the entire screen.If I boot in safe mode, I can see icons, but the taskbar is not visable, and clicking on the icons does nothing. The keyboard works in both cases. This is very difficult to troubleshoot when I can’t see anything!