Successfully installed KernelEx 4.0 RC 2 on Windows 98 SE (Slovenian). Problem At first boot a file 'C:\Program Files\Common Files\Softwin\BitDefender Scan Server\bdss.exe' reported 'wrong operating system'. Fix >right clicked the file >clicked 'Properties' >clicked 'Compatibility' tab >clicked ' Disable KernelEx extension for this program' check box to enabled it >rebooted Then installed Firefox 3.5 and enjoyed using it. Many thanks for this highly appreciated solution.