Hi shmox
Working with Softice i see hunh? welp your in for a ride if you heading into Softice studio 2.6 and up.
firstly consider these steps...
1.) install bare bones softice that will run at all on your machine.{if it runs make exastive notes in a note book of all the settings}
2.) why do the above, well softice is fun, but it's also something else that needs to be mentioned really clearly here, it's all about ENGEENERING, so it's fun but it's also a deep well,you have to study and use good study techniques
IMPORTANT !!!
3.)once you got the basic softice{non studio version running}
then get all the bugs out, save your registry{export it to desk top and save it}
4.) learn everything about adding things properly to the registry[read the help file with in regedit] always start regedit from RUN box accessed by start button.
5.) installing softice studio is all about indexing one thing with another, im one of the few people who can even get the mouse working properly and that seems a simple feature, but i happen to love it

cause it wirks goood hehehe
look
C:\Program Files\NuMega\SoftICE Driver Suite\SoftICE
in this folder is a file called SIWSYM all you do with this is compare what you see here in the registry because softice is going to automatically set this up any how, you will notice some differences from time to time, make notes {again this is engineering software take it all serious if you want the fun to roll on and on}
sounds like college GOOD study SKILLS
TAKE NOTES
COMPARE NOTES
DO RESEARCH
i think you see the picture now...
ADDENDUM:
most of the problems i always had with softice was configuration of winice.dat and drivers settings having to do with screen modes or interupts.
thats all i know about it shmox and the second part of your problem there about dos heres a secret, your gonna love this one ,if all else fails use softice on it self{INIT="X;"}<- see this
you will find it in softice winice.dat file
HST=256
DRAWSIZE=2048
INIT="X;" <- change it to lets "SUMEG1" instead of X so it looks like this
INIT="SUMEG1;" <- all this does is tell softice to not boot to windows and stay with you in the debug editor. all the things you ever wanted to know about GDT,LDT,IDT are all in here
and yes i went to mit and western newengland and greenville techical institute and have associates degree so i do have some idea after taking windows OS systems NT Administration and windos NT OS systems design and machine language
so i tell it like it is.
i hope this helps tons, save this post your going to need it in the future... bye for now write me here or at james20202@netzero.com have an awesome day !!!