I am sorry to hear you are having problems with this configuration but let me help you.
Checking the information you have provided, there are some recommendations I would like to give you:
- Update the bios in your system using the latest one from the computer manufacture.
- Check some information about known issues at the following link:
It is also important to mention that when using video convertors/adapters the performance can be affected or in the worst case may not work at all.