Insanely Jumpy Pings/Latency

Well, yeah I play about 3 different games mainly.

GunZ, cs;s, and L4D

Now, it would be nice to play the game without having my ping go from constantly 50-500. I have tried downloading my network controller drivers from the official Realtek website, that didn't work. Dusted out my PC, Reseated my processor, even took out my Phenom 99950 and put in a AMD Dual core 5000+ x64 processor to see if that would work, still a no go. I have my windows updated fully. I'm running Windows 7 Ultimate 64-bit.. so yeah. o_O It'd be really nice to fix this problem before the weekend because I have a tournament that I have to play in GunZ on the weekend, got a big chance of winning this one too :] Anyways, help me out if you can, or atleast give me some advice. I had called my ISP to see if they were doing something wrong, they said they would send out a repair man to check up on my modem and everything, he found nothing wrong. So I decided to go out and buy a new Linksys Modem for a hefty 70$, the problem then went away for about a good week or two, but now it's back and worse then before. I used to only go about 40-110. Now it's more along the lines of 40-500+. Even on vent I'll spike to about 1.5K ping, which is really insane and ridicoulis. Anyways let me know if you can help out.

How long have you had 7 for?
Have you tried disabling all firewalls temporarily and then having a go to determine if this is the cause?
Are you using wireless or wired? Im going to guess that your using wireless as you say your ping fluctuates a bit, wireless is bad for gaming mmmmk.

Actually.
I have tried turning off my firewall and antivirus.
I am running a wired cable, nothing is wireless. I do not spike on Vista/XP. :/ I really like Windows 7 though compared to XP + Vista. I recently downgraded to XP Pro 64-bit till I can figure out the issue.. so yeah.
Basically I'm thinking it's something to do with one of Microsofts Windows Update patch/security fixs, because each time after I do a Windows Update on W7 I start to get the insane spikeing.

I have the same issue on windows 7 with CS:S, COD4 COD5... My server browse lists are all 400+ pings, in game I ping "normal" around 50ms on close servers, but then all the sudden spike to 350+ or higher.

I've got windows firewall turned off, i've got no antivirus software running while i play games.

what gives guys?

This has been suggested many times on this forum but to be sure - have you tried disabling autotune?

Open a command prompt as Admin and type in "netsh interface tcp set global autotuning=disabled" without the quotes.
If this makes things go bad or nothing changes then just put it back to the way it was - netsh interface tcp set global autotuning=normal

Turning off net tuning does not help.

No one has any thoughts on this at all? Out of all the users here and specifically geared towards Windows 7 and very little replies??

I tried that command prompt thing, it didn't work at all.
I even went through the REGISTRY and tried to figure out if something was out of place or some sort, nothing. I think it's only the Realtek Gigabyte Ethernet Controller, everyone who has that controller on W7 has this spike issue so far, as from what I've heard/learned.

I have the Realtek PCIe GBE Family Controller.

I downloaded the drivers from ASUS's website, as the card is on my motherboard.