"the strange thing is that is works perfect sometimes."
Well, this is new information.
We're just not getting anywhere with this. You need to give a full trouble-shooting report, which includes:
1. Temporarily switching off everything that could possibly be interfering with your downloads, inc. firewall & antivirus and any background processes that need heavy I/O.
2. Watch CPU and memory with Proces Explorer or similar while downloading.
3. Give full info about the above, and also a proper list of exactly what you've tried already and how. "The settings with the lines didn't work" is too vague - exactly what did you try?
As I said, the more info the better.