Help with slow connection speed please

[DBissett]

I'm having a problem with one computer. Uverse delivers 14 Mbps and all devices in the house except for one computer get that. This one computer (I'm on it now) gets about 3 Mbps. A UVerse technician came over today and installed a new gateway and narrowed the problem down to this computer. I've replaced the cable and just installed a new NIC card, with no change. What's left? Could it be the motherboard needs to be replaced to solve this problem? (ATT mailed a new gateway earlier in the week and immediately after setting it up this computer also got about 14 Mbps for a few hours. When I retested 12 hrs. later the speed had dropped to where it is now, which is where it was when I first requested the service call.) Thanks.

 

[DBissett]

I just ran CCleaner and the problem seems to have gone away. But the speedtests are all over the place. I tried running the test in MSExplorer and the speed looked fine. Ran it in Firefox and it was down, then up. Ran a bunch of speedtests in both browsers and almost all of them were up to speed, but occasionally a test would come in about 2 Mbps. Ran speedtests at InternetFrog and speed was back down to 2 Mbps, then MSExplorer and FFox were OK. The inconsistency is amazing.

 

[Elixer]

What OS you got on the machine that seems to have issues?
For now, the best way to troubleshoot this is to boot up a "live"linux distro (boot CD/DVD or thumbdrive), and do some tests.
That will eliminate the current OS & drivers.
If all goes well there, it is possible you have spyware/adware/virus on the one machine.
Run spybot search & destroy (free), Malwarebytes Anti-Malware (free), and see if those turn up anything.
If not, I would create a new partition, and install a new copy of windows there (for testing). Boot from that partition, and see how it goes then.

 

[DBissett]

Thanks Elixer. This morning as soon as I turned the machine on I ran speedtests in both Firefox and Explorer. Firefox showed 3 Mbps and Explorer showed 15. My Firefox has been automatically updating for a LONG time, so I did a fresh install of that and it seems to be behaving much better....it gave a speedtest reading of nearly 15 immediately. I'm hoping there was something funky about FF and that this corrected the problem. For now anyway. Win 8.1 and I have Malwarebytes active.