There are different ways to install iGO8 on your device.
Download an iGO. This one would be a good choice.
http://www.navitotal.com/showthread.php?6880-Igo8-March-5-2011. When it isn't, we can always switch to a different iGO.
Unrar so you will have a folder called iGO with the program files in it. You can copy this complete folder to an sd card or to memory, but the difficulty will be to start iGO properly.
Therefor first try this trick I learned only today.
You will need a SD card. The device won't recognize bigger cards than 2GB. On 2GB SD should fit all continent maps, but you can select what maps you need. Simple as can be. Or you pick a smaller one, like 1 GB or even 512MB. That is okay too but will limit the content size (lesser maps etc)
On your PC, just copy everything from within the igo folder directly on a 2GB sd card. Thus NOT the complete iGO folder as is always done, but the contents of that folder.
Next rename the igo.exe to "Autorun.exe", put the SD in the Becker and reset the device. Since Autorun.exe is used to update the device from sd card by Becker, this will start iGO automatically. This will do no harm to the device itself. It will just run iGO, no more. First test without maps, see if it works, set up voices etc.
Report back how it goes, please. When there is an error, tell us what message you get.
I hope this works. It should, but I never tried this procedure before.
When iGO functions as it should, it will spare you all unlock procedures, mortscripts, setting up paths (BTW: for possible later use SD on becker 7934 is called "Storage Card")
Oh. Possible disadvantage will be a problem related to igo on becker.Turning off (not reset, just turn off the device) while running igo, when power on will freeze the device (or iGO). The side lights will turn on, but the screen will remain black. There is no cure I know of and you will need to reset the device to get it working again.