During SDK installation, the environment variable PIXELINK_SDK_ROOT was created for you. It is set to the root directory of the SDK files.
For example, if you installed the SDK to C:\Program Files\PixeLINK, PIXELINK_SDK_ROOT will be set to "C:\Program Files\PixeLINK".
Checking the Value
You can view the value of the environment variable several ways. Two easy ways are:
1) From a command prompt (cmd.exe) (also known as a DOS window)
2) In the System Properties dialog (Windows Key + Pause/Break, or right click on My Computer, then select Properties, or, under Start, Settings, Control Panel, Settings) go to the Advanced tab, and click on the Environment Variables button.