Don't know what's happening:can Connect with Master System but Slave drops connection

Hi, I have two Desktop systems with WindowsXp and connect to DSL via a Router (for the Master System) and a Wireless Adapter Card (for the Slave System) and would appreciate your help.
I am able to connect (and stay connected) with the Master system, it operates just fine but I have a problem with the Slave System. When I try and connect to the Internet with the Slave System (i.e. I click on IE), a connection is made but the connection drops after 2-3 minutes and the screen says “The Page Can Not Be Displayed”.
This occurs if the Master System is shutdown or if it is connected to the Internet, matter of fact, if the Master System is connected to the Internet and the Slave System tries to connect, as I mentioned the connection for the Slave System drops after a few minutes AND the connection for the Master System is also dropped. If the Slave System is Shutdown, the Master System stays on “forever” (or until the Slave System tries to connect and then the connection for the Master System is dropped).
To get back on the Internet, I need to shutdown the Slave System, re-start the Master System, un-plug and then re-plug the Router and the DSL Modem.
I should also mention that when I look at the icon for the Wireless Card icon on the System Tray of the Slave System, it says that the connection is STRONG although the connection has been dropped!
I have done the following so far, I pinged both the Master System and the Slave Systems and the pings came back 4 packets sent, 4 received, zero packets lost.
I ran the (Trojan) Cleaner Professional scan and it scanned 131,198 files which were all clean. I then ran Ad-Aware and it found 17 objects (all of them were Cookies), which were FIXED and I re-ran the Ad-Aware scan again and it came back clean.
Next, I ran Spybot and it FOUND Webtrends Five, which I fixed then re-scanned the system and it came up clean. I performed a COMPLETE system scan with MS Antispywareand Beta and it came up clean.
Again, the Master System connection works fine as long as the Slave System is shutdown but when the Slave System (tries to) connect, it only stays connected for a few minutes and the line is dropped (and if the Master System is connected at the same time as the Slave System, the connection on the Master System is dropped.

I have no idea what is going on? Is there an infection? Is it faulty hardware? Are some settings amiss and would be appreciated ALL the help / suggestions / advice,… and sympathy that anyone can offer. Thank you in advance for your considerations,
Bob

 

Don't know what's happening:can Connect with Master System but Slave drops connec

Thanks Ron, since I did not get any responses, I thought that I might be posting on the WRONG forum. I am in dire need of help so wherever you feel that this request should be posted, is fine with me. Thanks, Bob