Hi ta2jac,
After checking the Technical Specifications of your computer model, we found that your computer qualifies to install Windows 7. However we strongly recommend you to run Windows 7 Upgrade Advisor.
See Dell Dimension 3000 System Technical Specifications
If you've restored the computer and if you're able to boot the computer to the desktop, then we recommend you to download and run Windows 7 Upgrade Advisor to check if your computer qualify to install Windows 7.
If you want to run Windows 7 on your PC, here's what it takes:
• 1 gigahertz (GHz) or faster 32-bit (x86) or 64-bit (x64) processor
• 1 gigabyte (GB) RAM (32-bit) or 2 GB RAM (64-bit)
• 16 GB available hard disk space (32-bit) or 20 GB (64-bit)
• DirectX 9 graphics device with WDDM 1.0 or higher driver
See Windows 7 system requirements
Visit our Microsoft Answers Feedback Forum and let us know what you think.