Is Mactracker wrong about the Mac Pro 1,1s? It says Apple claims they can have 16GB of RAM, but can have up to 32GB.
I'd never heard of MacTracker. Thank you for letting me know about it!
From what I can see, MacTracker says, under "Maximum Memory", "32 GB (Actual) 16 GB (Apple)", which is consistent with what I found on my web search. I was more concerned though with how little memory he might have rather than how much - hope for the best but plan for the worst as they say - so I was searching for what the base RAM might have been for this model back when it was sold. What I'd read was that this was either 1GB or 2GB, depending on the model. If that's all he has, then the experience of running Windows 10 would be miserable, and with 1GB he wouldn't even be able to install x86-64 Windows 10 at all. I thought that was worth adding.
But I agree with you though. Getting any basic Windows machine for about $200 USD would be much better than doing anything with that Mac Pro. A quick search on Amazon brings up a Dell OptiPlex 705 with 16GB of RAM, Core i5-6500t, Windows 10 Pro mini PC for $150 USD (https://www.amazon.com/Dell-OptiPlex-7050-Micro-Bit-Multi-Language/dp/B08GCX4JKJ/) . It'll run circles around the MacPro, and it'll be cheaper to operate, and it looks like it'll take up almost no space because of how small it is. They have even cheaper options too.
For the battery (if that's what's wrong with it), it's easy to replace. It's a common CR2032 coin cell battery, and takes about 3 minutes to replace. https://www.ifixit.com/Answers/View/128046/Changing+a+Battery+in+mac+pro+3.1
Nice to know on the battery, and it looks like it's super cheap to get one. It also looks considerably easier to work with than when I had to replace the clock battery on my iMac G3. 🫣
I still don't think it's worth the cost and hassle though to purchase and replace the clock battery, hard drive, and possibly get a RAM upgrade as well. All that together would likely cost more than an entirely new machine. It looks like he's simply bought himself the wrong computer for what he needs it for and it seems we're in agreement that he's better off getting an entirely different Windows PC.
It's probably also worth adding - relevant to both trying to install Windows on this Mac Pro and getting a new PC - that most of the additional requirements for Windows 11 are artificial and most machines that can run Windows 10 can also run Windows 11 just fine if you disable the additional hardware checks in the installer. But Windows 11 no longer comes in a x86-32 build, and the x86-64 build now officially requires 4GB of RAM. Windows 10 will get security patches until October of 2025.