The first thing I would recommend is....
Try clean booting the system and see if that produces any relief. Run it like that for a day or two and check Windows Update manually in the interim to make sure everything is up to date.
https://support.microsoft.com/en-us/kb/929135
Use the steps for Windows 8 / 8.1 (same for Windows 10)
Easily done and easily undone.
You're basically just disabling all Startup Items and all non-Microsoft services. Do no mess with the Microsoft services. Be sure to check the box to hide them before proceeding.
Then obtain the 1511 ISO from here
https://www.microsoft.com/en-us/software-download/techbench
Windows 10 at the top of the list not single language at the bottom, correct language and bit version.
Use ImgBurn from here
http://imgburn.com/index.php?act=download to burn it to a DVD or Rufus from here to burn it to a USB ThumbDrive
http://rufus.akeo.ie/ to create your installation media. Use that media to run setup.exe from within your current version of Windows to perform the in-place upgrade.
In advance of attempting the upgrade, this time, disconnect any and all USB connected peripherals, printers, any USB Dongles supporting wireless keyboards or mice and especially any that support wireless networking. Leaving only a wired USB keyboard and a USB wired mouse.
AND if you have any third party security suite software installed….. uninstall it completely including running the vendor specific, proprietary removal tool (Google it).
Early in the Upgrade process you will see an opportunity to download updates as part of the process.
DO NOT do that, so…. Uncheck the box or choose not now, or do this later or however it is presented just choose the NO response (it’s been a while so I don’t remember exactly how it is worded.