Welcome NewSun!
I don't think that the service option matters, all you need is the v2.22 core, and the correct flags (assuming you have an eligible GPU, I don't remember what you are running, sorry)
If you don't have the 2.22 core, shoot us an e-mail address and we can get you the core file. It is as simple as navigating to the location where the 2.25 core is currently running from, and swapping them out. We can rehash those directions when you get the file.
Micro isn't a fan of it, but if you aren't totally committed to running as a service, you can convert over to the v7 (7.2.9) Client Control, and it will manage both the CPU and GPU folding, and it is a really sweet package, it works great, and couldn't be any easier to setup. Your choice!
If it helps, I have not added any hardware, and didn't lose any production switching to v7. And now with these monster beta units, I am very near getting my wish for just 1 day over 100K.
I just wish I had an eye catching visual to highlight what I am referring to....

"Friends don't let friends dial-up"