I have had wireless internet (2mb) for just over a year now, have had multiple problems involving signal strength, but fixed them by buying a new antenna.
 
My computer is not on site in the house, it is in a large outbuilding about 20 meters from the router.  Since buying my new antenna I have had no problems with connection, but i have always had problems with large lag spikes during playing online games , which is driving me INSANE!!!. I have checked my bandwidth, using various tests, and they all say I am getting full bandwidth.  I know it is my wireless, as I have tried indoors via cable, and had no problems.
 
If anyone knows any solutions to this problem it would be much appreciated if you could share your vast knowledge. Thanks in advance   .
 
P.S. I am using a Dlink DWL520+, and have tried with a Dlink DWL 510, and still get the same problem...

Lag could be cause by a background application/service spiking processor usage.
 
Run performance monitor and look at your CPU usage ... (Start -- Run -- Perfmon). Do you see any regular spikes ?

My % processor time does not spike unless I am doing something, which I would expect is normal.  My AVG. Disk queue length does not spike unless doing something. My pages/sec sometimes has a small spike to about 40, but this is much less frequent than I would get a spike during a game.

Actually, looking at it again i dont have any spikes at all, left it for 5 mins idle, and none whatsoever.  Should I be running something?
 
I have checked for spyware etc...

I suspect your problem may be wireless and not processor related. What do you mean by "large lag spikes", i.e. how big is the lag (in milliseconds) and how long does it last?
 
You might try running a long ping from your PC to a wired PC connected to your router and see what the variation is.  An easy way to do this is with Pingplotter PingPlotter.

The lag spikes can go up to about 600ms i think and lasts for about a second or 2.  It is quite frequent though, happening every 5-10 seconds or so

Try running in 'Safe mode with networking'
Do the lag spike disappear ?

It's only in games that I get the spikes, and I can't play them in safe mode.

Try running   MSCONFIG    and checking what stuff is running at startup.
Could be an item sitting in your system tray that is polling the internet ?

I have experienced the same problems. I've been playing WOW over a wireless connection for about 2 weeks, my ping will be nice and low but the game seems to freeze for a second or two.
 
On closer inspection I found that the lag spikes happened when my wireless card renegotiates the speed if theres a drop in signal strength
It's still connected but it alters the speed.
 
I think it only happened when I let the Belkin utility manage the network connection and it was fine if I let XP do it.
 
It was only noticable in games, surfing or file transfers were untouched.
 
I fixed mine by going back to my wired connection.
 
Metatron

Good point !
 
You could set your wireless card to a fixed low speed, rather than leaving it to Auto sense. May help ....

thanks a lot sounds like a good idea, I will try it and reply soon...

It didnt work, I still have the same problem.
 
But thanks anyway

Are your motherboard chipset drivers up-to-date ?
Do you have the latest drivers for your wireless card ?
 
Does your wireless card have packet burst ? (disable it)
click me !

These are my advanced options, can you please tell me if any of them are packet burst:
 
Authentication mode
Desired basic rate set
Desired BSS type
Desired SSID
Desired supported rate set
Desired TX rate                                      (I know what this is)
ERP protection
Fragmentation Threshold
Mode 4x
Mode 4x mixed
Power mode                                           (Is set to continuous access mode)
RTS threshold
Short preamble                                      (Off)
WEP option                                             (I don't use a WEP)
 
Thanks

Hmmmm .. don't think any of those are packet burst.
 
Here's an interesting forum. Take a look and see if it helps you
Click me !

Not really but thanks anyway, I'm gonna try reinstalling drivers again.

I think metatron nailed the problem identification and fix. There is virtually nothing you can do to affect the way that a wireless client monitors and adjusts its wireless connection. Even if you force a transmit rate, the client will periodically check to see if there is a better access point around that it should switch to.
 
For example, Broadcom-based adapters periodically drop throughput to about zero like shown in the throughput vs. time plots in this review:
http://www.tomsnetworking.com/Revi [...] T54G-9.php
 
This happens even with best signal strength.
 
The only thing you can do is try an adapter that uses a different chipset. The D-Link DWL520+ uses a TI chipset. Most any other 802.11g card is going to use a different one, since TI is largely out of the retail adapter business. Any NETGEAR card that has 108 in the name will use an Atheros chipset. Maybe try one of those.

Thanks a lot    
 
I will purchase a new card as soon as i have the money and means to. i.e a debit card!!!! YAY

Don't get too excited - odds are a new card isn't going to solve your problem.  The problem is that wireless equipment just isn't as efficient as wired.  There is a physical delay whenever something travels over the air, and regardless of how good your signal strength is, you'll always have lag over a wireless connection.   This is compounded if you are talking about a WISP rather than your home router - having worked with that kind of equipment for a living I'll tell you that its performance can be good, but will never match a hardwired solution.  This is especially apparent if the transmitters are loaded down with subscribers, or are having to work hard to reach customers at the edge of its operation range, reflection, interference etc all play a part.    
 
If you want to get rid of the lag from your pc to your router, then I would suggest burying cat5 between the buildings (they make special burial cable for this and you don't need to go deep, just 6 inches will do) - just remember to call digsafe and get your property marked before you dig (mark your expected path in white paint, dashed lines a few feet apart)
 
From there, if you are on a WISP, swtich to cable or DSL.

I kind of have the same problem. I was on hard-wire to a linksys router when we switched to a wireless belkin router. Since then everytime I get on counter-strike or any online game like that (nox, hl, ect) the moment I get on I cant play. Every 2 seconds it spikes from 30-50s to 700 ms and then I walk back 5 feet.  Its pretty much impossible to play. I ran a cat5 wire to go hard-wire again hoping it would fix it and I still get the problem.
 
*note*
 
I have not reformatted since we changed to wireless so something with wireless messed up the game.
 
Is there an option I need to change to get a constant connection to steam?