Incidently, this assumes that you can trust the current environment. I'm not sure about his application, but someone could just do a set USERNAME=fake_name, and foobar his code. Not to mention if he's using RunAs or somesuch, I have no idea how the Windows environment handles that.

His use of Win32::LoginName() appears to have been correct.

From the Win32 pod:

Win32::LoginName()
Returns the username of the owner of the current perl process.
[download]

Tested on Windows XP here, it does what it claims. So yeah, I'd say Win32::LoginName() is what he's looking for.

Update:Converted pre tags to code tages.