See tip 8415 » How can I set a user's default printer in a batch script?
and links in the 'Tips & Tricks' at http://www.jsifaq.com
"HKCU\Software\Microsoft\Windows NT\CurrentVersion\Windows"
Value Name is Device
This type REG_SZ value has a default string value of PrinterName,winspool,LPT1:.
When set for a network printer, the string value is \\ServerName\PrinterShare,Description,LPTn:.
The description is not important so the string value can be expressed as \\ServerName\PrinterShare,,LPTn:.
