Hard line network adapter slow

I have google fiber and the 1Gbit internet. When they first installed it, my up/down was 900+mb. As of a few days ago I am getting only 90ish/mb down and 450mb up. I did unplug and clean out my computer as I do ever couple of months and had the issue after I conected everything back up. The Google tech came out today and hooked 3 different laptops up to the ethernet cable going to my computer (2 of his and my daughters) and was able to get 900+ up/down on all three. Hook mine back up and same 90ish down 450 up. I also have the ISATAP issue that all the forums (including Windows) says is not an issue that will cause a problem with your adapter. Need help please!:confused:


Tech Support Guy System Info Utility version 1.0.0.2
OS Version: Microsoft® Windows Vista™ Ultimate, Service Pack 2, 64 bit
Processor: AMD Phenom(tm) II X4 955 Processor, AMD64 Family 16 Model 4 Stepping 2
Processor Count: 4
RAM: 8190 Mb
Graphics Card: ATI Radeon HD 4800 Series, 1024 Mb
Hard Drives: C: Total - 476937 MB, Free - 237575 MB; D: Total - 476937 MB, Free - 388958 MB;
Motherboard: ASUSTeK Computer INC., M4A79T Deluxe
Antivirus: Lavasoft Ad-Aware, Disabled