It seems like you are facing compatibility issues with your eSATA drivers after upgrading from 32-bit Vista to 64-bit Windows 7 on your Dell XPS 420. Here are some steps you can take to troubleshoot and potentially resolve the problem: 1. Check Device Manager: - Go to Device Manager and check if there are any unrecognized devices or devices with exclamation marks indicating driver issues. 2. Driver Installation: - Ensure that you are installing the correct drivers for your system architecture (64-bit). Sometimes, drivers meant for similar OS versions might not work due to system architecture differences. 3. Compatibility Mode: - Try installing the drivers in compatibility mode. Right-click on the driver setup file, go to Properties, and then the Compatibility tab. Check the box for "Run this program in compatibility mode for" and select Windows Vista or Windows 7. 4. Intel Rapid Storage Technology (RST) Driver: - The Intel Matrix Storage Manager has been replaced by the Intel Rapid Storage Technology (RST) driver for newer operating systems. Try downloading and installing the latest version of the Intel RST driver compatible with Windows 7 from the Intel website. 5. Check RAID Settings: - Ensure that the RAID settings in the BIOS are correctly configured. If RAID is causing instability, you may need to reset the BIOS to default settings and try installing the drivers again. 6. BIOS Update: - Confirm that you have the latest BIOS version installed on your Dell XPS 420. If not, consider updating the BIOS to the latest version available from Dell's official support website. 7. Seagate Pro Compatibility: - Ensure that your Seagate Pro drive is compatible with the eSATA configuration on your system. Some drives may have specific requirements or limitations when connected via eSATA. 8. Driver Signature Enforcement: - If you encounter issues during driver installation, you could temporarily disable driver signature enforcement. This can sometimes help with driver installation issues on Windows. Try these steps sequentially and test after each step to see if the issue is resolved. If you continue to experience problems, please provide more details on any error messages or specific behavior when attempting these solutions.