FYI for future tech support issues, please contact the office directly at 800.576.GMAT or
gmat@manhattanprep.comI don't think there is a way to reset that test - though don't take my word for it, since I know very little about tech stuff.
Call the office or send an email so that our IT team can tell you for sure. The good news is that there isn't actually a limit to the number of tests that you can take. It is the case that, after 6 tests, you may see questions that you've seen before, but if you have an entire test that didn't really have any questions, then you're less likely to have that happen.
I don't actually recommend taking more than about 6 tests total, and 2 of those tests should be the free GMATPrep tests (made by the same organization that makes the real test) - so you're fine!