I don't remember - that NTD executable is not being run over HTTPS, right? See http://support.microsoft.com/default.aspx?scid=kb;en-us;312546[^]. Same symptoms, it seems. One other idea occured to me. Grab the SP2 assemblies including and related to IEExec.exe and disassemble them with ildasm.exe (on the command line, use the /out:filename.il along with the assembly path to disassemble to a file). Do the same with the SP3 assemblies and diff the similar .il files. Looking in the assemblies (using either ildasm.exe or .NET Reflector) I don't see anything off hand about why this would fail. Most likely it's a client side issue, from the sounds of it, in which case 9/10 fingers point to IEExec.exe like you have diagnosed. This posting is provided "AS IS" with no warranties, and confers no rights. Software Design Engineer Developer Division Sustained Engineering Microsoft [My Articles]