Hi, I reverted back to 16612 and it failed with cfgmgr32.dll (from the net) just like before with the new Ros cfgmgr32, same errors. So I went back to 16603 using cfgmgr32.dll from the net. Oh yeah it worked. So somewhere between 16603 and 16612 something changed in setupapi. I have to revert the whole ros tree, so this did take allot of time to check. Our cfgmgr32 current svn is the same as the one from the net, so I have ruled it out as suspect. Any Ideas? James