Thank you for all your replies. After some work I was able to figure out what was happening. Just a word for all those who are still looking for the settings. You have to copy all the dlls in Windows/System directory. For some reason mine didn't accept the path variables that I set up in the environment varibales. OK so that was quite simple, however my real question was to execute the program within Visual studio, which after some twiquing I was able to do it. The key to this work is how your environment variables are set up. PTC distributes a batch file along with their Pro/I toolkit "environment" install (this is different from Pro/I toolkit install). Now you have to run your executables through this batch file otherwise it won't work. After some time spent and some feedback from PTC I got that one right (Environment varibales in my company are different than the defaults that come with std batch file). Now I went in and set up the varibles that Pro/I toolkit needs so that I can run my program from Visual Studio (I got help from PTC. if you are interested, visit http://www.ptc.com/cs/cs_23/howto/itk1151/itk1151.htm). But it just crashed in some dll, without even giving me error number or whatever. I am just guessing that I there are more variables I have to set than it is mentioned in the document that I just attached. If anybody else has got such a problem and has a solution please let me know. If anybody knows how to run the toolkit application within visual studio, w/o going through batch file, please let me know. It's pretty long mail.. But I guess if archived, it can be helpful to new users.