You did a Windows System Restore to a previous point and are using the same HM3 database you were using before the Windows System Restore?
You shouldn't need to reinstall to try and fix this but even if you did reinstall HM3 using the Windows Add/Remove Programs method it will only remove the program files. It will not affect your personal HM3 settings or databases as those are stored in your \Users directory.
Please try all the steps
in this FAQ. If you continue to have problems please zip and email the problem original hand histories and tournament summaries to us as instructed. Make sure you also include screenshots of your reports/filters and a detailed description by tournament number, session, hole cards, filter, stat, etc. of some of the errors we need to test.