Wireless works in safe mode but not normally

I upgraded to Windows 7 recently glad that the nightmare of Vista was over. Was using my ol' 9800 GT and the internet worked flawlessly for a while. Unfortunately, the VRAM on the card died, and my primary GPU, a GTX 460, is in the process of being RMA'd. So, I bought a spare video card in the meantime: a XFX HD Radeon 4650. After I switched video cards everything went to hell. 90% of the time internet doesn't work at all in normal boot, and when it does, it's like this:


However, the internet quality in safe mode is great:



The wireless adapter on the computer experiencing these problems is a WMP600N. The wireless router is a WRT160N. The modem is an Arris TM402G, and we also use a Vonage VDV21-VD. The ISP is roadrunner. The distance between my access point and I is about 40 feet. There are a couple fish tanks, walls, a television, a nearby microwave, and a lit up christmas tree between me and the router.

Things I have done:

I. Several reformats
II. Ran several tools to completely remove nVidia drivers.
III. Tested a wired connection on this computer, worked fine.
IV. Moved the wireless adapter between PCI ports.
V. Dozens of power resets and hard resets.
VI. Malware scans with multiple searching and removal tools.
VII. Downloading the Ralink 2860 drivers as they are more updated than the WMP600N drivers linksys provides - they share the same chipset.
VIII. The solution that poster #8 (anonymous) shared in this thread: Windows 7 and linksys WMP600N - drivers - Windows-7
IX. Disabling different/all applications/services while running the computer and on startup.
X. Checked if there was any channel interference: Imageshack - inssider2.png
XI. Tested for overheating. Nothing ever runs over 35-40 degrees Celsius, aside from the old 9800 GT that died, which used to get extremely hot(75+).

I can't figure out how to install Windows 7 without creating windows.old - I have a hunch that it's carrying over software/drivers/something that I don't want, because after the first fresh install when switching from Vista there were no problems whatsoever. All my hardware should be in my profile I typed it all out when I was registering, but ask if you would like to know anything. As I have been reformatting frequently, I haven't committed to installing a firewall. I never have malware problems, any more, anyways. Windows Firewall is all that I'm using. As of right now, I'm using the RT 2860 3.1.8.0 drivers; the download in poster #8's solution in the tomshardware thread I shared earlier in my post no longer works. I believe this is identical to the driver I downloaded: Ralink RT2860 drivers for Windows 7. In observation, device manager shows my network adapter as WMP600N and not Ralink 2860, even after installing drivers manually. I've installed very few programs and I've run all the windows updates available. I'm posting on this forum in safe mode with networking, right now.

Thanks for any help in advance!

Sorry if it's lengthy, was trying to share as much information as possible about the situation so people would have a clear idea of what's going on.

Thanks for sharing.

Do you reckon I should get started with a clean install, rich? Because I don't mind trying it.

Alrighty, I will get started on it now and post back once I'm clean. Thanks.

The internet works, but latencies spike upwards to 10,000 while running applications.

Any advice on how to deal with spiking ping/latency?