Problem With Wireless

I just got a new wireless card for my p.c. (D-Link). It works perfectly with my web browser, but when I use SL my connection to the router is lost every couple of minuets and it takes a long time to reconnect. A few days ago my dad suggested to change the position of the antenna and that worked, but only that day.

SL over Wireless is unstable ... a known situation.

That's documented in the Knowledge Base: http://secure-web9.secondlife.com/knowledgebase/article.php?id=027

Besides other things they write:
So you may want to play around with the WLAN settings of your equipment

I know for fact that DLink is one of the worst wireless you can get. I use Belkin for wireless router and use my laptop's built in wireless antenna (HP Pavillion). I've had no problems whatsoever when in SL, that is, other than your regular SL problems. So perhaps, you should explore switching to something other than DLink.

I've been using a belkin wireless router for almost 4 years now, never had problems. They can suffer is there is a heavy electrical equipment being used, or in the path of the signal (microwaves, washing machines, unsheilded speakers), you might also check that no one is 'piggy backing' your router and using it for their system. You can check that in the connection section. I assume you have used the WEP secure connection protocols to prevent this? There were tales not long ago of people being able to use your wireless connection by using a 'Pringles' tube and a bit of wire as an antenna, hence why you should check they aren't sucking the signal to download their porn stuff.

I can run SL off of my laptop no problems using my Belkin hardware but never managed to get a stable wireless connection to SL when using the PC. PC keeps the connection when browsing and even when downloading at full capacity on a 10 MB connection from IRC, Newsgroups, P2P etc but never with SL, so there is definitely a quirk with SL and wireless technology in some isolated cases but I cannot explain it. even with my laptop next to the PC the laptop would keep the connection to sl fine and the PC would constantly drop the connection, so I know its not intereference from phones or the microwave etc as the laptop works all the time and the PC worked all the time whilst not connected to SL. Just gave up in the end and wired the PC back to the router.

This isn't an advertisement for Belkin, but that is the wireless router I use, and I have no issues with wireless connection to SL.

Check to make sure you have all your port settings correct for your router. Make sure your port settings apply to all the IP addresses that your wireless computers use. When I first used SL, it took me a while to figure out the proper way to configure the router.

Of course, make sure the port settings are correct for any firewall software you use, too.