>The harddrive serial number changes each time the hard drive is formated. So,...
>
>Vlad
>
>>How many people here use hard disk serial numbers to control installations? What methods do you use to control security?
>>
>>David Turnedge
>>Sydney, Australia

Hi David,

It may sound really smart of me, but I actually stole the idea off someone on the Universal Thread a while ago. Still, doesn't make it any less useful, although the problem mentioned by Vlad is a real one. I haven't actually used the method yet, but I almost certainly will. Again, the link on the thread suggested the following:

Use this programme suggested in one of the replies to my message to determine the serial number. On the first time after installation, get the programme to find the serial number, perform an interesting calculation with it, e.g. serial number / 7 * 8.450 + 33 or something, and let the user send the result of that calculation back to you. Then you can back-calculate what the serial number is and perform yet another calculation to give the user a number that will be stored in a table in their application. On entry, the new calculation will be performed and if it matches the number stored in the table, it lets you in.

Problems occur when the application is moved to another hard disk or computer, or as Vlad said when the disk is reformatted. They'll just have to contact you again for a new validation code. It seems pretty secure if you ask me.

Rene.