Windows 10 Practically unusable

[RawSharksRunescape]

I was on my pc working fine for a few weeks, getting a few updates between those weeks, then all of the sudden I noticed my pc slowing down (would click on a program it wouldn't ever open or it'd take a while to respond to open). The programs and clients opened would stop responding every 5 seconds, etc. and it kept getting worse and worse til now it's unusable practically completely. It's also taking 10 minutes+ just to boot.
My Pc specs are: I7 4790, 16gb ram, and r9 270 OC

 

[basroil]

You either have some sort of disk failure or a virus.

Check the disk's SMART status using the manufacturer's tools (respective websites), and if that checks out do a full virus scan

 

[nitrium]

Press ctrl-shift-esc (advanced options) and check your disk and cpu usage. If any app/service is using a lot, there's your culprit.