1. Do a 4POS backup if you can : c:\4POS\4POSBackup.exe
2. In control panel - Programs - click on 4POS - Repair
3. Run 4POS upgrades (From where you saved it or normally under c:\4POSUpgrade\4POSSqlExeUpgrades.exe)
4. open 4POSScan to see if it is > opening
5. If it opens - close & restore your 4POS backup
6. Open 4POSbackoffice & do update POS
