I have a Pentium III machine running Win98 with 1 fixed hard-disk (C:) & 1 removable hard disk (D:) of the same configuration. There is also a Sony DVD-rom which uses PowerDVD driver. (E:) When I boot up with all of the above, the system runs fine. However, when I shut down, remove the removable hard-disk, set the CMOS to Auto for Secondary hardisk, the system boots up OK albeit slower. I still can use Win98 fine except the major problem is when I attempt to use Windows Explorer or 'Find' or 'Browse', the system hangs. Before it hangs, on the Device Manager I notice that C: drive & E: drive are available. Should not the DVD-ROM use the D: drive-letter rather than E:? Could this be the problem? Also when the DVD-ROM is physically disconnected such that only C: drive exist, there's no problem. Anyone can help?

This is a little goofy, but it works on my Asus-Lx board. Don't allow the BIOS to detect the removeable drive and allow Win '98 to detect it instead. On my machine the drive ends up beyond the CD drive letter, so when it is removed it makes no diff the the drive letter sequence.

As far as I know your Drive letter assignments go as thus ; floppies, harddrives, ramdrives [not sure 'bout that one],CD-Roms and removable drives [e.g. Zips, Jazz etc. but these can change by default and can be changed to user assigned] ,this of course is in Win95 so I suppose Win98 should be the same [but don't bank on it] Just curious, why do you remove the removable HD or do you mean a disk or is it a parallel removable drive ? You could also check your jumpers. Are your HD's on the same cable, i.e. Master and Slave, if so change them to Primary Master and Secondary Master, this might stop the hang [My 2 HD's hung for 3 minutes at startup and 5 minutes at shut down before I realised it and changed them around]. And when using Auto-Detect HD if your DVD is on that list change it to 'not installed' or 'none' or whatever it is, this should not effect anything because it is for Hard Drives.