If you are using older versions below of ESET Smart Security 4.2.54 on windows Vista and in Windows 7, then you can get “ESET Personal Firewall initialization Failed “ error, the fix to this is to download and install the new version or running of ESET released ESET NDIS Repair Tool on your Computer which fixes this problem.
You can know what version of ESET Smart Security you are using by visiting this page. This issue is caused by corrupted Microsoft Windows Registry that contains NDIS driver information. Due to this, all software installations (includes ESET products) NDIS drivers will be not successful.
How to Permanently Disable Personal Firewall in ESET Smart Security 7
ESET NDIS Repair tool will repair damaged registry entries and allows NDIS drivers and programs installation using these drivers.
Download the ESET NDIS Repair tool and run it to fix this issue.