Odd problem logging into W98SE

Using W98SE Version 4.10.2222.A
This is a family pc. My wife, 2 kids and I each have separate identities.
Generally quite reliable and doesn't give too many problems.
Except when my wife logs into her profile. The windows system page
(C:\windows) opens automatically. It can be closed by clicking the X at top
right corner and she can then proceed as normal. This only happens in this
particular profile. I cannot find any reason why this page should open.
The problem occurs when she logs out and another user logs in.
After a while the pc will crash and a restart is required.
This ONLY happens after logging out of my wifes identity and into a
separate identity.

Any ideas please why this is happening and more importantly how to stop it?

Many thanks

Sunbeam