|You can try checking for newer drivers for the device and if there are some, apply them to it.|
Barring that, there's likely not much you can do aside from:
a) Moving the computer closer
b) Replacing the existing wireless NIC with a better one
c) Connect with a network cable to your router
Yes, I get that the laptop appears to have better signal strength. This could be directly due to it having a better piece of hardware (NIC) than what you're using in the PC so comparing the two is like comparing oranges and apples. Both are fruit, but they dont' taste the same.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.