Problem Installation Sims 3 (Basic Game) = 0x80040702. [SOLVED]

Hello guys!
I'm having a problem installing the Sims 3 (Basic Game). It all starts with step 7 of the installation guide:
''7. When, during Installation, the Istallation asks for Disk 1, click 'Browse' and select the 
StartDisk you have Mounted. (NOTE: In 'My Computer' or 'Computer' the StartDisk is
called 'SIMS3')''
When I select the startdisk I mounted it says nothing was found, try again. 
So next, I tried step 8 (''8. When again asked to insert Disk 1, click 'Browse' and select the Disk 1 you have Mounted.'') and it seems to work! But... when the installation is almost done, a screen occurs with the following message* and the installation is cancelled.
I don't know what to do now. Did I do something wrong? What can I do to fix this? 


*Unhandled exception
Error number: 0x80040702
Description: Could not load DLL: DSetup
[b style="font-size: medium;"]Setup will now exit.[/b]

I think you may want to redownload. That error looks like something may have gotten corrupted while being downloaded.

Okey I'll try that, thanks! 
How do I keep the download from being corrupted again?

When I look at information about my download (in utorrent) it already says 'lost:34,6 kB' and the download is only at 5%. 
Is that the problem? How do I prevent or stop that?

No error this time! Problem solved, thank you!