[edit] Just saw the two posts on this page. See next post to find your files. :amused: [/edit]
1) You have to turn ems memory emulation off.
either static (one time action, but you might have to change it back in order to play other games):
open your dosbox.conf in your DOSBox program directory (simply via the shortcut in the Start Menu if installed so) and change ems=true under the [dos] section to ems=false, then save
or dynamic (in every new DOSBox session, but "no" problems with other games):
>config -set dos ems=false
2) In DOSBox:
>mount c [ultima directory]
>c:
>ultima7
No installation needed!