I am attempting to install WIN98 and WINXP Pro as a dual boot system. I created partitions for both, then installed WIN 98 with only minor problems fixed in the System.ini. I have a valid licence for both WIN98 and WINXP Pro. When I begin a new install of XP (not upgrade) I get a "Invalid Product ID" error. It is definately not an invalid key. I can install XP by itself with the product key and it works fine, but not after Win98 in resident. The only way I could get it install was to hide the partition that Win98 was on, but then I could not get back to that partition to unhide it. So essentially I did not end up with a dual boot machine. I tried using a the Acronis Disk Director OS Selector (Boot manager) to install XP and still have the same problem with the key. Could this be an issue with the MBR? It there a way to hide the WIN98 product key? I deleted the registry entry from Win98 but I don't think that it was the problem. I have looked through hundred and hundreds of threads trying to see if anyone else has had similar problems but nothing. Can anyone offer some suggestions. FYI I need Win98 to run old 16 instrument control software so I have no other options. Tried VMWare as well. No go.