2 replies to this topic

[mspa]

When I install a product with i.e. the product code:
{B47DFDFE-8B2F-4F93-A6F9-DED43DC86843}

The registry will contain an entry in the HKLM\SOFTWARE\Classes\Installer\Products with the product code:
{EFDFD74B-F2B8-39F4-6A9F-ED4DD38C8634}

As you can see they are totally different. Well actually not totally different because when you take a closer look, the seperate value parts are mirrored as shown below:

B47DFDFE 8B2F 4F93 A6 F9 DE D4 3D C8 68 43

EFDFD74B F2B8 39F4 6A 9F ED 4D D3 8C 86 34

My question now is, why is this done? and is it always done with the same algoritm?

[Stefan Krueger]

I guess it's done so that nobody tries to mangle with these registry entries. It looks like it's always the same algorithm, but it's not documented and may change any time without notice.

[Dattel]

afaik - the last 3 years it was the same algorithm to "crypt" the Product Code. It has never been changed since that day