Debug startup program behavior

I want to Debug a program called Freecall in my Windows 7 Professional laptop. Now it shows as a Startup item in "System Configuration" console. I tried to uncheck it in the Startup item and restart, but it keeps on adding itself to HKCU\Software|Microsoft\Windows\CurrentVersion\Run. i think its the same for Yahoo messenger..these programs keep on adding to startup even after I manually deleted the entry from the registry. I want to debug and find out if after starting开发者_JAVA技巧 the executable, the program writes to the registry. How can I do that? Is there a way I can run the binary in Sandbox mode? Are there any VS tools for this?

You can use Process Monitor to figure out exactly what the process is doing w.r.t. registry accesses. If you want to debug the application while it's starting, you can use the GFlags utility's "Image File Options" tab, where you can specify a debugger to be launched instead when a specific application is executed.