Wi-Fi doesn't work on computer that was used to set it up?

I bought a wireless router and used my computer to set it up. The Wi-Fi works on my iPhone, my boyfriend's iPhone, an my boyfriend's computer. However, it only works on my computer for a few minutes. After that, it disconnects and I have to use the Ethernet cable for Internet. What can I do to fix this?

What is the make and model number of the computer?
·What is the service pack installed?

Follow the below methods:

Method 1:
Disable the security software and the firewall temporarily on the computer and then try to connect to internet.

Note: Antivirus software can help protect your computer against viruses and other security threats. In most cases, you shouldn't disable your antivirus software. If you have to temporarily disable it to install other software, you should re-enable it as soon as you're done. If you're connected to the Internet or a network while your antivirus software is disabled, your computer is vulnerable to attacks.

Method 2:
Follow the steps from the below link: Troubleshooting network connection problems: http://www.microsoft.com/...shoot.mspx

Method 3:
Also try resetting TCP/IP protocol and check the results: How to reset Internet Protocol (TCP/IP):http://support.microsoft.com/kb/299357

It seems like your Wi-Fi has some hardware level issue but anyways you can give try to fix this issue as follows: I would recommend you to go on your manufacturer's website to download the latest driver and update your driver.