Don't laugh! If you prefer Windows 7 this is a cheap way to get into a really solid PC. I've used these recently and while they are not gaming boxes, they are very snappy for general use. Proof that Win 7 runs perfectly fine in 2GB of RAM as well. No crapware either.
The Dell Optiplex line is built like a tank and highly serviceable. Thankfully this is not the slimline model.
While it is listed as "refurb", since it comes via the Microsoft Factory Authorized Refurb process it is likely "off-lease". Microsoft's leased PC's tend to come from clean office environments vs. other off-lease sources where you don't know.