Try renaming the existing system registry and then reopen SWX. It will create a new system registry. I have seen this trick solve a ton of problems just as you described, especially since you have done multiple installs/repairs your registry could be polluted.
Ccleaner also may help to resolve some of registry issues.
One more comment: the SW Student Edition works much better if you install it from Administrative Image.
During installation you have the option to create the Administrative Image first.