The code below works correctly when executed in "user" mode (Compatibility Mode Windows XP SP2 ) and returns a handle to LPT2
lpPrinter->hPort = CreateFile(_T("LPT2",GENERIC_WRITE | FILE_READ_ATTRIBUTES, FILE_SHARE_READ, 0, CREATE_ALWAYS,0,0);
The identical code fails when given Admin privileges and returns invalid handle and error code 2 (file does not exist),
Does anyone have an idea why this happens?
I should have added that LPT2 is mapped to a network shared generic text/only printer via NET USE LPT2 \\servername\sharedname /user:adminname adminpassword where "servername" is another win7 pro workstation sharedname is the printer's sharename and adminname and adminpassword are the credentials for the administrative user on servername. The net use command is issued from an administrative command prompt.
See the last comment here -> CreateFile function | DaniWeb
Another thread with some diagnostic ideas to try -> Parallel port communication - C++ Forum