Hi Chris,
Please run diagnostics on the system to confirm hardware functionality. Here are the steps:
- Restart the system and immediately start tapping the 'F12' key to enter the 'Boot Menu'.
- Use the 'Down Arrow' key to highlight the 'Diagnostics' option. Press the 'Enter' key.
- The diagnostics will begin. Please note the exact error message/code, if any appears on the screen.
If there is no hardware failure detected, then possibly the Windows has crashed and needs to be reinstalled.
You can recover data from the hard drive, for this you can purchase a hard drive enclosure and connect the Dell XPS 8100 to it. Then connect the enclosure to another system and backup the data. You may refer to Service Manual of this system for removing and reseating the components. Please follow the safety instructions before replacing the components.
If you are not comfortable doing this, then I suggest that you take assistance of a professional to back the data. Hope this helps.
Please reply back with the test results.