Internet slow on new computer?

[Robert]

I just built my new computer on the 26th of December and I had it take to a friend of mine 2 days ago to install Windows 7 as I couldn't figure out why it would not install. Turned out to be a kinked SATA cable. Anyways, my internet speed has been ridiculously slow since then, I installed all of the Windows updates taking me about 2 days. I am using a TP-LINK 300Mbps TL-WN951N V.3 adapter. All my other PCs seem to run normally. I have installed the drivers. One from the website, and the other on the disk, just to make sure they wouldn't be bad or anything. Avast took me about 45 minutes to install last night as my laptop or other pc takes about 3-4 minutes. I have tried I.E. 10, Firefox, and Chrome, all slow. Any help would be appreciated, thanks!

[polar vortex]

Have you run CHKDSK (check disk)?