About the errors themselves:
The EMS error you get has to do with the fact that XP doesn't have an expanded memory manager. Expanded memory was a way for DOS programs to address the memory and it's not available in Windows newer than Windows 98 SE.
Getting the error "disk full" when you try to save has most likely to do with the fact that HDs are much larger now and when the game tries to compute how much free space is available, it can't and gives that error.
There's no other easy way around this than to run the game with ScummVM as suggested by Gabez and The Tingler.