Win 98 is not, itself, as stable as XP and IE gets so woven into the system that it often cannot get out of its own way. You can do the usual disk cleanup...empty cache and remove cookies. You need to remove spyware and, especially, "browser helpers" (a definite misnomer). This may help some. If the system is getting older without a fresh complete reinstallation in quite a while, this might be warranted. Win 98 and IE6 isn't going to get much attention from MS, I suspect.
I have occasionally gotten a pop-up dialog box saying "IE has encountered a problem and must be shutdown",and then it asks you to "send a report" which I do.However,the last 2-3 days I get an average of 3 of these a day.In the detailed information it says there is a solution in "SP2" for XP and I will paste the other comment.Is this Microsoft's way of forcing us to upgrade?My OS W98SE IE6SP1
For Windows 98, Windows 98 Second Edition, Windows Millennium Edition, or Windows 2000:
A solution or workaround is not available for the problem you reported. Microsoft is actively working on the issue and will provide information when it becomes available