I have just found that Microsoft Security Essentials under WIndows 7 is detecting the file c:\softrak\ledger\LedgerFinRep.exe as a Trojan horse and quarantining it. This then causes the error message you see. If you look into your softrak\ledger\ folder, there will be no LedgerFinRep program.

Excluding the c:\softrak folder from MSSE's realtime scans and reinstalling GL helped on one system. Restoring the quarantined LedgerFinRep.exe file and adding an exclusion for that particular Trojan Horse fixed it on another.