Wireless Internet Keeps Disconnecting

I'm not sure anyone can help me with this problem, my internet provider cant seem to, but will give it a shot....
Microsoft Windows XP Pro
Version 2002
Service pack 1
Intel Pentium 2 processor
400 MHz
128 MB of Ram
Just got a new laptop, so I ordered a wireless modem from Bell Sympatico, now the internet seems to log off every 10 minutes or so, sometimes closing the browser and restarting works, sometimes not and I have to reboot, this is starting to drive me crazy, I have been on the phone with Bell at least 10 times, the other night for two and a half hours, they seem to fix the problem and then an hour later it happens again, thats the reason I have been on the phone with them so much, I'm on a Siemens SpeedStream 6520 wireless ADSL Gateway....

The laptop gets cut off the net sometimes, but not nearly as much, I have run tons of virus and malware scans, like Panda, Ewido, Adaware, Spybot, Anti-Virus, makes no difference, before I got the wireless modem I had zero problems connecting with the internet and staying connected, any suggestions? God knows Bell cant seem to fix the problem....
When I get the 'Page Cannot Be Displayed' message, I still get this in my taskbar:
Wireless Internet Connection
Speed: 100.0 Mbps
Signal Strength: Excellent
I'm at the end of my rope, Sympatico says the modem/router or whatever it is works fine, I dont know what else to do....

 

My network connection box, and the internet connections box, should that one be empty since I am on wireless?
Hmmm, my attachments didnt work....

 

Have been experiencing very similar issues with my D-Link Wireless network. Even replaced my network card in case it was the problem....no joy. Uhhh, one question, are you seriously running Win XP on 128 Mb RAM ?? One thing we have found that definitely interferes is our portable house phone. Have tried 3 diff phones, 900 MHz, 2.4 GHz and now have a 5.8 GHz, all with the same result. As soon as someone answers the phones the router locks up. Perhaps some of the real smart people on here could shed some light on the possibility that running low RAM on XP could be your issue ?? Not a lot of help, sorry, but will be watching your post.

 

Actually, I made a mistake, I should have posted I have 256 Mb, not like that is a huge difference....I'm not sure about the RAM making a difference, I ran a regular modem for years on 128 Mb, but maybe using wireless makes a difference, maybe someone here would know....