Extremely frustrating internet connection problems

I'd be very appreciative if someone can help me with my current problem. It's been driving me absolutely crazy for weeks. Basically I lose my internet connection periodically. Sometimes there are large chunks of time, like a few hours, when it works perfectly, but most of the time it comes on for a few minutes, then goes out for 5, 10, 20 minutes at a time, comes back for a minute or 2, then out again. I can tell when it's connected or not (aside from refreshing my browser over and over again) from my skype systray icon which goes from green to gray in its attempt to reconnect. However, according to my Dell Wireless LAN card utility, I never lose connection with the router; it's a constant solid green strong connection.

I've eliminated malware as the cause (with the R&R procedure here).

About my network. Well, it's DSL and it enters through the apartment across the hall (my roommate's father's apartment), then comes into my apartment where the router is. I connect with wifi. My roommate also connects only with wifi but she's only here for a day or 2 per week. She did mention she had internet problems as well, but with so little time I couldn't confirm this week if her problems were identical to mine.

Now I have very little contact with her father. (I'm in Germany BTW and my German is not very good. His English is non-existent. I mention this because it's not so easy for me to go over there and check the modem, or even ask him about his internet experience. I did however go over there a bit the other day and browse and I notice that a few times, the browser also failed to connect with a webpage).

I'm wondering if the problem I'm having is with the ISP? Again though, with the language barrier, calling them and dealing with them is... a bit stressful. So I'd like to eliminate other possibilities before I pursue that.

OS: XP
Router: USRobotics
ISP: FritzDSL

Some more info:
I have uTorrent installed on my machine. About a month ago I followed online procedures for port forwarding. Around the same time (can't remember if it was before or after actually) I noticed that whenever uTorrent was running I would suddenly lose connection with the internet, but it seemed to go away as soon as I closed uTorrent. Shortly after that the current problem started. I haven't opened uTorrent in weeks.

Not sure what else to add here. Again I'd be very appreciative of anyone willing to help. This is extremely frustrating. I'm just hoping the internet holds out long enough for me to post this

 

Halo covered a good bit of ground.
Here's some left field ideas.
How about possible interference with the wifi signal - appliances, phones, etc.
Try changing wireless channels on the router and comps.
Power settings on the network adapter. (Wake on Lan settings.)
Same thing happen in Safe Mode with Networking? (Less drivers loaded.)

 

Halo, many thanks for your response. I'm happy to say, first off, that the problem was apparently solved by rebooting the modem. I actually would've done that sooner if, as I mentioned, I wasn't a little apprehensive about trying to communicate with my roommate's German-speaking father where the modem is located. Fortunately I have the key and am welcome to go over there when he's not.

However, I would like to have your assistance securing my network connection, either with WEP or WPA according to your recommendations, as we've left it unsecure this whole time out of simple laziness. To answer your questions:

1. Windows XP is up to date. Do network drivers update automatically or do I have to do that manually? My laptop is a Dell Inspiron 1501

2. I did notice when I was across the hall that there was a firmware update prompt. I would have updated it myself but it was in German so I was reluctant to proceed. I'll pursue that this weekend.

As I mentioned, rebooting the modem corrected the problem.

3. The router is USR5463. Please help me secure it.

I'm not sure if questions 4 and 5 are still relevant, but I'd have to go back and look anyway, so let me know if I should please.

 

Halo is usually pretty busy but there are very few more knowledgeable around here so if I may make a few suggestions.

#1
You can go to Dell Support directly and use the service tag number off your comp to check on any driver updates. Microsoft updates generic drivers so the ones from Dell should be for your specific machine.

#2
The firmware can be updated for the router from a site I will give you below.
This should be done from a computer that is wired to the router rather than wireless.

#3
Here is a good site for a wireless security checklist - EZLAN

I would read it first to get an over all picture of security. Remember that if you set up security, all comps will need to match the set up exactly to access the router wirelessly.

Here is a link to the support page for the router - USR5463

If you click on the "User Interface Demo" on that page you will get a good set of interactive screens to show you what the router configuration pages look like. (In English)

One of the first things to do would be to change the router's default log on username and password. This will make the router configuration pages more secure.

Additional info - To get the MAC number for your network adapter, go to START > RUN > type in ipconfig /all and it will be listed as part of the information displayed.

#4 & #5
I think since the wireless connection is working, you can dispense with checking the lines and filters.

Hope this helps.