I have the same problem. In order for my internet to work, I need to lift my laptop off my bed or desk or whatever.

if you have a long enough ethernet cable and a basement (even if its just a crawl space like my house.) just connect your comp directly to the modem. its the most reliable way to get internet to your comp.

http://www.ncix.com/products/?sku=69169&vpn=TL-WDN4800&manufacture=TP%20Link&promoid=1062

Check that out it should be perfect for you if you want to go that route.

I have a desktop.

If it's just now I'd highly recommend simply starting your computer.

If that doesn't work I'd still suggest you'd start with the simpler solutions such as;
Restarting your router, reconnect to the network or forget about the network and then reconnect.

Ive never used a USB wifi card.
But...
This one looks good? Maybe http://www.amazon.com/Medialink--150Mbp ... +wifi+card

Do you have a laptop or a desktop? because if you have a laptop Whats wrong with your internal wireless card. If you have a desktop don't get a USB one try to get a PCI adapter they are faster better built and have better range.

So should I get a new USB wireless card, and if so witch one would you guys recommend?

A virus typically wouldn't affect your system unless you obviously copied the infected file to your computer.

Try getting a new router such as a 802.11n or 802.11ac instead of a 802.11g?

Probably has nothing to do with anything :/

I have CCleaner, also my brother did have a virus on his computer, but this happened before he even had the virus. ._.

USB wireless cards are notorious for dropping signal, if possible try using the on-board wireless card. If that is not possible try a wired connection to the modem this will help determine if its your computer or your wireless card, if you do try that just hooked up with an Ethernet cable and go about your regular activities for the same amount of time as is the average before you would typically lose internet.

If it still loses internet after that amount of time get yourself something like CCleaner and clean up your temp folders and internet caches they can sometimes strangle out your internet connection. (also a virus scan couldn't hurt)

My personal experience (so you know I am not just someone making things up) : 6 years working in multiple computer shops and computer hobbyist.

Mmmm he's about 30 feet too, he might be a little closer.
When I restart my router it stop for a few hours.

Have you tried restarting your router?

is your brother closer?
to the "internet box"?

From my modem (I call it my internet box, don't know if I'm calling it the right name) it's about 30 feet.

To my modem?

how close are you to the device