Hello and welcome to the forum.
I am sorry to hear about the problems you are running into.
As this is primarily a user to user forum, not official Technical Support, someone-else may chip in. But please remember that the same symptoms do not necessarily mean the same problem.
If that folder on disk contains the Syn2 library then the instruments should be picked up by a Rescan. Make sure that you have Registered the Syn2 CS Serial number, using the IK Product Manager. And, run the Custom Shop Program, log in, click on your Account Name and select "Restore my purchases".
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If that does not work, the best thing to do is
Search the FAQs first, via here. If they do not resolve the issue, there is a
red button link to the Technical Support form, for some one to one investigation and help. Response time aims to be within 2 working days (US (East Coast) Business hours, generally), but in the current circumstances please allow some more time.