32bit hexadecimal number which represents unique computer signature. It is calculated accordingly to locking parameters and application signature project settings. Site code is always formatted as zero padded 8 characters long hexadecimal (valid characters: 0-9, A-F) number (XXXXXXXX).
Machine ID (MID) code
Digital representation of locking parameters on remote machine. Machine ID has the following structure: XXXX-XXXX-XXXX-XXXX where each XXXX represents 16-bit hex value (for example: A19F-8A20-F19D-19A8).
Machine ID (MID) contains encrypted information about locking parameters from remote machine.
Machine ID (MID) goes in pair with Site code. Different Site code will result in different MID for same computer. For example, when license is removed, protected application will generate different Site/MID codes on next run.
MID code also depends on project settings (application signature). This is to prevent generation of invalid activation codes based on wrong project settings. For example, application is protected with project A but wrong project is mistakenly loaded (B) for generation of activation codes.
Site code and MID code can be merged into single site-mid code by enabling "Merge Site/MID codes into single code" option in activation dialog customization settings.
Machine ID (MID) code decoding
MID code is encrypted for security reasons. In order to extract locking parameters we need to decode MID code. This can be done in PC Guard's activation panel.
We need both Site/MID codes in order to be able to track changes in locking parameters on remote computers.
Why is this useful? What can we do in case end user claims that he lost his license because his hard drive has crashed or he had to format HD for whatever reason? After re-installation of protected application it now displays different, new Site/MID codes and requires new activation code (requires reactivation).
MID code decryption can help us in determining if new site/mid codes are coming from original computer by comparing original (based on original Site/MID) and new (based on new Site/MID) locking parameters.
This process can be done manually in PC Guard's activation panel by clicking on "DECODE" button after entering Site/MID codes.
Same process of decoding and comparing machine locks is automated in Activation center (ACEN) where end users can reactivate their licenses based on rules set by ACEN administrators.
Application will generate different Site code / Machine ID (MID) codes on each computer.
Applications sharing the same application signature will generate same Site/MID code pair on same computer.
Applications protected with different application signature will generate different Site/MID codes on same computer.