[French]

I'm not at my home computer so I can't try anything else you might suggest right now, but I'll try to answer your questions so you can better help me.

I'm using Windows Vista.

For the string, in the DOS window I change my directory to the directory where I have my ebooks stored.

mobidedrm nameofbook.prc newnameofbook.prc PID

Without the > in front of the PID I get the check sum error. With the > I get a new prc file with 0 kb size and another file with my PID as the name that can be opened with Notepad and it basically spells out what the command line should be.

My PID has 2 letters at the end of it...so if there is some kind of "checksum" going on, and as the name would imply it is a calculation of sorts, I don't see how my PID can be valid with this script since the beginning of the PID is numbers and the end is letters.

Hope this helps.

ETA: My PID is 10 digits long including the letters at the end.

Also...I don't if I mentioned this...the device I'm using is a Blackberry. I have Mobipocket installed on the Blackberry so the PID is for the Blackberry.

ETA (again): I tried the string with several different books that have been purchased at different times and I couldn't get any of them to work. The error was always the checksum error.