screen sharing from Windows to Mac over LAN What software do I need to install / use on a Windows box to be able to remote desktop into OSX locally on LAN?

Versions don't matter really, but to be specific: OSX 10.7.5, with "VNC viewers may control screen..." enabled, Windows can be any flavor of 7 or 8.

As it has to be local but also because of the policy, I can't use commercial / free TV, CRD, LMI, etc. on the Mac side, and prefer not to install anything on the Mac as it already has a built-in VNC server (as well as ARD installed). I can however install viewers / clients on the Windows side.

Tried Real VNC (including Enterprise trial) - it gets stuck on the login screen and I can't get past it.

Any ideas are welcome - thanks in advance.

(Tried to find threads that ask (or answer) this exact question but couldn't find anything. Regardless - apologies if this is a duplicate.)
According to Real VNC support, this is a 10.7 issue. I sort of confirmed it by successfully using Real VNC to connect to 10.6.8 and 10.9.3 hosts. Regretfully my Mac Pro (2,1) is too old in the tooth for OS X 10.9.x, so I have to figure out a different solution.