Can I load DOS 6.22 on my new computer running Win98 w/o incurring any system or software conflicts? I ask because I tried to load an older version of SimCity and got an error saying I needed an ems driver . . . this thing has xms; what's the difference??

First, try to run that program in a full-screen DOS session. Windows will previde EMS memory for it (you can adjust the amount with right-click/ "Properties"/ "Memory" tab, set EMS to "Auto" (best) or whatever amount it needs. If needed to run in real DOS mode, easiest way is to right-click/ "Properties"/ "Program" tab/ "Advanced" button, check "MS-DOS mode" and "Specify new config", click "Configuration" and select "Expanded memory (EMS)". this way, when you double-click that program Windows exits to real mode DOS with appropriate drivers to provide EMS and runs the program. Alternative is to install EMM386.exe in CONFIG.SYS, but the previous method is better. About installing DOS 6.xx: as you see, you don't need it. And by installing DOS, some critical system files are replaced and Windows yill run no more.