All computers on network but one have horrible upload speed

[Hazyrd]

I tried uploading some videos to youtube the other day, and my internet took a poop. I couldn't browse or do anything. I had to power cycle my router. The odd thing is it only affected my computer. I obviously started trying to find the problem, and I started with a speed test. I pay for 30mbps down and 3mbps up. I'm getting my 30 down, but only getting 0.2 up. So I started power cycling everything from the modem to the computers. I checked every computer on the network. Now here's the odd part. My girlfriends 1000 year old laptop, which is connected wirelessly, gets the full 3mbps up. I tried my desktop, and my friends desktop, which are both wired. I tried my friends laptop wirelessly/ wired. All but the ancient laptop gets awful upload speeds.

Called ISP, they sent a tech. He did some stuff and checked with his laptop, and he got the full 3 up, checked the line and hardware, said there is nothing wrong and left. I've been doing hardcore research for like 2 days now and have found absolutely nothing. All computers on the network are using the same browser and antivirus.

The kicker here is when we first got the service about 3 weeks ago, we had the same set up, and everything worked fine for everyone. The only difference was that the router was plugged into a different outlet.

Here is what I have tried so far:
Power cycled router, modem, computers
Bypassed router
Tried plugging router in old outlet, and other locations
Used wireless adapter to connect desktops wirelessly


I have absolutely no idea what's going on. Anyone have any ideas?

 

[Emerald]

have you checked your computer for rootkits, viruses and spyware?

 

[Hazyrd]

I have my computer set to do a full scan every single day. So I haven't actually scanned just to check this, but I've been clean as far as I know.
My computer isn't the only one though. So I really don't think it's malware of any kind.