As for dxdiag.txt .... follow directions as per Skuzzy below.
Here are the steps to do this:
1. Go to "Start" from the Windows desktop
2. Select "Run" from the pop up menu
3. In the Run dialog box, type DXDIAG and press <ENTER>
4. After a few seconds the DXDIAG utility will be ready (the progress indicator in the lower left corner will disappear).
5. Run the video and sound diagnostics (Select the Display and Sound tabs to do this).
6. Press the "Save All Information" button
7. This will save the DXDIAG data to a file of your choice
Step 8~ I (ChiLLi) am editing (original post was for email)
8. Once you have done this, simply attach the file to a post for us to look for any issues your system might have.