Its a new Mobo, Proc, Memory and one new HDD and new GPU.
I took the two old HDDs out of my old rig and put them in the new rig. So, in reality I didn't reinstall Windows I'm still using the same copy of windows.
All my games are still here but they are on the old HDDs in the same case as all the new stuff. I just want to move Steam from the old HDD to the new HDD.
In that case, only uninstall it after copying the Steam folder, or else the uninstaller will delete everything. You don't need to move your saved games anywhere, but I'd back them up just in case the uninstaller decides to delete them.
After you do that, then reinstall Steam to the folder you copied to the new hard drive.