since I've got a new computer my download speed has become complete shit, it's usually between 0.1 kb/s to 1 kb/s.
when I run speedtest.net the results are 38 mb/s which is obviously much higher.

any idea on how to fix this?

That's such a broad question it's extremely hard to answer.

You need to be more specific:

- What are downloading?
- What internet plan do you own?
- What is your ping?
- Is it always that low?

If speedtest is showing higher than your download speed, then the problem is on something between you and the server you are downloading from. I wouldn't sweat it.

If you really think it's your problem, then try running the same download from different computers within your network and see if the speed is similar (you may have to try several times to get enough data to rule out random spikes and congestion).