Can you get into Safe Mode? If so, then run MSCONFIG. Go to the Services tab. Check the box to hide all Microsoft services. Now disable all services that still show on the screen. Now reboot.
If you can now get into Windows the normal way without it crashing, the culprit was one (or more) of the non-Microsoft services.
To see which one (and to prevent it from crashing your computer), go into MSCONFIG and enable one non-Microsoft service. Then reboot. If no crash, go into MSCONFIG and enable another non-Microsoft service. Then reboot. Continue doing this till you find out which one causes the crash. Then go back into Safe Mode, run MSCONFIG, and disable that service. (And make a note of the name of that service, for future reference.)
You have now found the culprit. To make sure that there are no other culprits, if you have not finished re-enabling all of the non-Microsoft services, continue the above till either (1) you have re-enabled all remaining services, or (2) you have found more culprits.
After going through all of this, you should uninstall the software that is associated with the offending service(s).