Wireless Adapter problem

I have a little problem.
I connect my wireless adapter to my laptop. It connects to my wireless network, but after a few moments it loses the signal, and after 5-6 seconds my computer freezes. I have to reset it. I noticed that the same thing happens too when i move the adapter.
I installed the newest drivers downloaded from the manufacturer's website, but this didnt help.
If I connect the adapter to a Desktop PC, the adapters behaviour changes. It works a little but then the computers stops seeing it as attached to my computer and I have to pull it out and insert it again in the port to solve the problem.
I tried it on other laptops too. The problem is the same on another HP laptop, but on a Acer laptop worked like a charm.
What do you think it causes this? Any solutions?