Use PROCESS EXPLORER from Microsoft's Windows Sysinternals to give you total CPU time. Even without touching the keyboard, you should be able to see exactly what processes are consuming all your resources, as well as disk and network performance. Like almost all Sysinternals tools, you simply run, and don't install Process Explorer.
Right click on the columns shown to "select columns". From the "Process Performance" tab, check to add at least "CPU Time", (and, I always add CPU Usage, Start Time, and Context Switches, among other additional columns).
Become proficient with Process Explorer, Process Monitor, and other Sysinternals tools and you can diagnose or fix almost anything in your PC. Microsoft bought Sysinternals, since these tools are used to create and support Windows itself. There are a number of videos and excellent books available as well to help diagnose any problem.
TIPS:
Admin vs Normal User
You can't get disk or network stats when running as a normal user, nor can you stop a process you don't own. So either start in, "run as admin", create a permanent shortcut that is designated to always run as admin, (hit the advanced button in shortcut properties", or restart the program from File: tab as admin.
Navigate directly to the registry or folder for that process
Hovering over many of the column entries allows you to see the complete strings without opening properties by hitting enter. Properties allows you to click on the autostart registry or file location, which opens Explorer or RegEdit to that location.
Catch temporary fleeting processes
Some processes come and go, so you can't always catch them. Slow down the update speed, and watch for the new red entries, which are newly created processes. Then hit the space bar, which freezes the updates, and then you can open your possibly offending process.
Speed up your system properly
For processes that continue to run, you can start Process Explorer days after restarting your PC, and the CPU time will show the accumulated CPU and other usage. This is handy for finding offending apps that consume tons of network, disk, or CPU usage that you are likely unaware of, that slow you down. Usually, the worst offenders are your antivirus or anti-malware protections.