1. I have T3500s running W7, 32-bit. Was planning to try to run W10 on them. I already have the hardware... and if I could run W10 on them, I might get another 5 years service rather than just taking them to the junk yard. 2. Using a Dell Reinstallation Disk, I was unable to get W10 to load. (Appeared to load, but when it looked like it was about finished it stopped and again asked "fresh install" or "repair"?. Tried it a few times... same each time.) 3. Checked Dell's driver support page... they do not have drivers for W10 on the T3500. Not a great surprise, as the T3500 is 2009 vintage. 4. Checked Microsoft's "hardware compatibility lookup" and T3500 is not on the list. 5. I know sellers have T3500s with W10 on them, so I asked one, "How do you do it?" One gave me instructions about getting some file(s) off of W7, 64-bit and then would be able to install W10 (??) But with Dell not providing drivers, some components would either perform sub-par (on W10's included generic/default drivers) or not at all. When W10 first came out, you could "upgrade your W7 installation" to W10 for free. Not sure how that worked with W7's already installed drivers, but that appears to be different from trying to do a fresh install of W10. ?? (As of May 2018, there was still a way to upgrade your W7 installation to W10 for free. You might search to see if that's still available.) All in all, I concluded it's likely more hassle than it's worth to try to run W10 on my T3500s. And if I were looking at the prospect of "spending any amount of $$$ on a T3500 to run W10", I wouldn't do it. Given that you can buy an HP Z440 for ~$400-ish and that it's 2015 vintage... (has SATA III, USB 3.0, faster RAM and some much faster CPU choices, whereas T3500 has SATA II, USB 2.0 and is 6-years older)... I'm using that as a guide for my own upgrades to W10. For the price differential, going with HP Z440 is a "no brainer". If you go that route, recommend you choose E5-1620 CPU or better. The 1603 & 1607 are slower and run slower RAM.
If available and the motherboard support it, go for the E5-1650 V3 that is a six core while the 1620 is a quad. https://m.cpubenchmark.net/cpu.php?cpu=Intel+Xeon+E5-1620+@+3.60GHz&id=1210
Following up to Scataphagos, I have had T3500 running Windows 10 fine for a long time now. (I bought the machine based on recommendations here). The first thing I did when I got the machine was wipe it and install Windows 10. Did you try the Windows 10 compatibility checker? There is a link in https://answers.microsoft.com/en-us...s/310e06a4-b181-45ec-ae6d-ee93a1632932?auth=1 It has been quite a while now and I forget exactly what I had to do, but I started by completely deleting everything from the hard drive, including operating systems, hidden system backup partitions if any etc., and installing Windows 10 from scratch. As I recall, it would not have worked by installing on top of what was there because there were too many idiosyncrasies/"features" in what Dell had put on there. I did not want any left-over Win7 hidden partitions left around getting in the way. As I recall that was necessary. I would avoid trying any any kind of upgrade installation that preserved or upgraded whatever it came with. Better to start from scratch. (You can still use an upgrade license as I recall). Maybe there were a couple of steps, I cannot recall for sure. It has always been flawless. I think sound drivers were a problem for a while but that was resolved. That was about the only issue.
Does not look like great value to me. Cpu not specified and very cheap second hand, ddr4 speed not specified,, slower modules quite cheap nowadays, 240gb ssd is almost given away free these days (just saw a 1tb nvme drive special for 100usd) this here is 1/4 the size and most likely a sata drive. I attach at most a 400 dollar value to that, even refurbished.
I tried to access that webpage but it asked me to do some additional verification by the phone, so there is really no way I can help you with all that matter. But nowadays PC are more than good to go by that $600 and nothing else. Just take a look at your trading needs and currenct PC's abilities.