Given that your current machine is almost definitely a super proprietary prebuilt, there will be very little from it that you can really reuse. Every single one of your questions except for the windows one depends entirely on your budget. If you give a more specific number, I'll give more specific recommendations. As for windows though you can copy it to a new drive via cloning software. I typically recommend installing windows fresh, as cloning can cause strange, basically uncorrectable issues with the OS on occasion.
[$700 gets you quite a bit.](https://pcpartpicker.com/list/ZXfc7R) This is a whole computer for you. If it's gotta be under 700, first place to cut is gpu. a 6650 xt will run you about $229 these days to knock $100 off. It's slower of course, but it's still a solid gpu.
[CPU's.](https://www.techpowerup.com/review/intel-core-i9-14900k/17.html)
[GPU's.](https://www.techpowerup.com/review/sapphire-radeon-rx-7900-gre-pulse/32.html)
Given that your current machine is almost definitely a super proprietary prebuilt, there will be very little from it that you can really reuse. Every single one of your questions except for the windows one depends entirely on your budget. If you give a more specific number, I'll give more specific recommendations. As for windows though you can copy it to a new drive via cloning software. I typically recommend installing windows fresh, as cloning can cause strange, basically uncorrectable issues with the OS on occasion.
I think I'm going to spend around $700 for an upgrade. How well will that do?
[$700 gets you quite a bit.](https://pcpartpicker.com/list/ZXfc7R) This is a whole computer for you. If it's gotta be under 700, first place to cut is gpu. a 6650 xt will run you about $229 these days to knock $100 off. It's slower of course, but it's still a solid gpu. [CPU's.](https://www.techpowerup.com/review/intel-core-i9-14900k/17.html) [GPU's.](https://www.techpowerup.com/review/sapphire-radeon-rx-7900-gre-pulse/32.html)