Hi,
Will try to explain it simply. Nothing wrong with win 7, it is windows, it's Microsoft. First thing to consider, is 32 bit versus 64 bit version. Do you really need 64 bit, do you have applications that require 64 bit. If not then go with the 32 bit version.
Now on to Links. The problem is about which videocard works best with Links under Win 7. So far the ATI cards come out in front. NVIDIA card do have some issues.
Perhaps down the road, either Microsoft or NVIDIA will make some correction and solve the problem. If I were you, I would hold on a bit before upgrading your windows. See if any of the issues get solved.
And yes the bulk of the problem is about drivers for the video hardware. It is a bit of a pain, changing drivers in windows, or should I say replacing a driver. Drivers are not always that easy to remove and replace. You might need an application to help clean out old drivers.
To sum it up, what works well with Links 2003 is Win 7 with an ATI videocard, preferably in the 4000 series, I think...
Robert