Dell OptiPlex 990 SFF, Windows XP SP3, Intel Core i5 3.30 GHz (256GB SSD, 4GB) | eBay
Refurbished: Dell OptiPlex 990 SFF PC - Intel Core i5 2500 2nd Gen 3.30 GHz 8GB 500GB HDD DVD-RW Windows 10 Pro 64-Bit - Newegg.com
Used Dell OptiPlex 990 SFF Desktop PC with Intel Core i5-650 Processor, 4GB Memory, 500GB Hard Drive and Windows 11 Pro (Monitor Not Included) - Walmart.com