PREVIOUS.DAT is read by RESOURCE.SYS. If its not available it gets created by a DLL when the PMSHELL starts up. It also gets refreshed if a full hardware detection is run.
It is possible to get an error that says:
Exception in Module: Resource Trap 0003
It may be because PREVIOUS.DAT is broken. Try erasing it (or backup it or rename it) and boot again.