Using the Erase entire database option via Help -> License when logged in as the AyaNova Administrator deletes all data except for reports, tax codes, the AyaNova Administrator account, global settings, and localization as in detailed in the AyaNova v3 Manual section “Wiping the AyaNova Database”.
If instead you want to be selective on what is deleted, than you would open each item and delete - i.e. open the workorder entry screen, and delete. open the next wo and delete, etc
ButI’m wondering if you are"throwing the baby out with the bathwater" - did you try the other suggestions I made such as repairing .NET, repairing IIS etc before going to such extremes as per http://forum.ayanova.com/FindPost3239.aspx?