I've seen several reports that Windows insists on starting in Safe Mode if, among other things, a crucial file has been corrupted or deleted.
That happens if you have been a wee bit too hasty in deleting a file that Windows 98, or a program running under it, needs.
Most likely it was one of those files that is shared by many applications. Virtual device drivers - files with the vxd extension, are one example.
Most uninstall programs will warn you that vxd files, or any other shared file, should be removed only if you like torturing yourself.
To determine whether a mishap with a critical file is responsible, run the System File Checker utility.
The best way to do this is to go to Start/Run. Then, type sfc.exe in the Open dialogue box and press Enter.
The System File Checker comes with a lot of options, but what you want it to do is to look for files that have been changed, corrupted or deleted.
Checker stops every time it finds something suspicious and gives you the opportunity to make necessary changes.
If File Checker does not solve the problem, ratchet up to a more powerful tool, the System Configuration Utility. MSCONFIG.EXE.
The utility, which you start by typing MSCONFIG.EXE in Run, allows you to choose scores of different ways in which to start your computer.
By judiciously using the various options presented you may be able to track down a device, program or file that is troubling Windows 98.
Your machine may also be acting up because the computer's BIOS does not support Windows 98. Start the computer and when information about the BIOS is displayed press the Pause/Break button. Write down the BIOS' manufacturer and the version present on the computer. Then go to the maker's Web site and determine whether you can download and install an update for the BIOS.