It isnt my program but it is the windows built in dsim that is doing the work on that, and there seems to be some odd bug where it takes hours and hours to run sometimes and other times it only takes 10 min.
Check the task manager and see if dsim is running at all and if it is if it is using any cpu at all. If it isnt using any cpu then it may have gotten stuck, but if it is still using cpu then it is still working.
I havent been able to find an answer of why it takes so long sometimes, it does use windows updates to download any files that it needs, so Internet speed and how many files and what size it needs will play a role in the time it takes.
Shane