I have an old IBM NetVista with an Intel PIII CPU and 512 MB of ram.  It also has a 20 GB hard drive.  I have been able to install DOS without any problems but it does not like Win98 or Linux.
 
When I try to install Win98 it goes through most of the installation process including the reboots but I never make it as far as a working desktop.  Near the end of the install process it asks for the userID and password.  I type both in and it says that it is configuring the system.  It then reboots, does a scan disk and picks up on the install process where it left off, at the userID/password screen.  I type the userID/password in and the cycle starts over again (reboot, scandisk, userID/password).
 
Linux does not seem to fare any better.  I boot from the CD/ROM using Edubuntu and it asks what kind of installation do I want to do.  I choose a workstation installation and then the screen goes black, never to return again.
 
Any ideas/suggestions as to what is going on?  It is very stable with only DOS installed.
 
many thanks

Have a look at the motherboard... there were a number of IBM computers that suffered from the infamous cheap capacitor fiasco.  Look for bulged and/or leaking capacitors.  If you know what you're doing with a soldering iron, you can buy replacement capacitors and fix the board yourself... that's the only way it will be worth fixing.  If you take it to a shop to have it done, you might end up paying more than the computer is worth to fix it.  (This of course depends on how many capacitors have failed... one or two isn't bad, but if a majority have failed, then it's cheaper to replace the board)
 
One other possibility is the power supply.  If you have a spare handy, it might be worth a shot.  Random freezing and restarts usually indicate a faulty power supply.  DOS obviously isn't very demanding on your hardware, where Windows and Linux are... which is probably why you're not seeing any problems in DOS.

I'm not sure of your familiarity of what I'm going to tell you but to sum it up involves CMOS Settings, HDD Preparation, and Installation of Win98.
 
CMOS Settings;
 
Disable OS2
Enable PNP
1st boot Floppy
2nd boot Hdd
 
HDD Preparation;
Use FDISK to delete ALL [Very Important, including Non-DOS], previous partitions, create a Primary DOS partition to install Win98 on enabling all Large disk support prompts along the way.[With a 20g HDD a Win98 Startup disk will do just fine]
Restart the computer and Format the partition you created
 
Then install the Win98 OP/SYS
 
All the hurdles should be eliminated and the install should complete, any thing you need you do not have including step by step instructions, bootdisk creating, Etc. can be found and acquired here.>  www.bootdisk.com