Hello Tim,
Welcome to web2py-users group !
Considering that you are new ! and probably you have not developed any apps yet in your web2py installation ( the 1.99.7 ) ...
you can simply make a new install of the latest stable version ( now is the 2.0.5 ) ... under another folder if you want !
the checking for upgrades button does not work and no one actually noticed it until it was time to upgrade to the latest version ( which is recently .. ) .. before the 1.99.7 (minus - ) it used to work fine !
That being said ! ... it should not stopped you from getting your feet wet with the latest web2py version which is awesome !
happy coding !
Don_X