Ok, first thing is to check and see if you have a network bridge installed on your machine.
Click on Start, Control Panel and find the network connections icon. Double click on it. In there you are looking for an icon that looke similar to this:

If you see this icon, then yes, you have a network bridge installed which can cause many crazy signs. One being slow internet access. To disable and remove the network bridge:
To enable or disable the network bridge
1.
Open Network Connections
2.
Under Network Bridge, right-click Network Bridge, and select one of the following:
• To enable Network Bridge, click Enable.
• To disable Network Bridge, click Disable.
Now, once you have the bridge disabled, you'll want to delete it so you don't accidently turn it back on again.
To remove the network bridge
1.
Open Network Connections
2.
Under Network Bridge, right-click Network Bridge, and then click Delete.
Both sets of quoted directions are direct quotes from Microsoft Articles.
Now, IF you do not see a network bridge icon, then as CaveDweller2 said, you may want to reinstall your wireless card drivers or even just updating them could be enough to get you back up and working properly.
@CaveDweller2 - You're killin me man