What's the easiest way to save Task Manager's Processes tab as a CSV file?

You can't do this using the task manager itself, but you can use the built-in tasklist command line program to do it. Open a command prompt (cmd.exe) and use the following commands:

• Type tasklist to output a list of all the currently running processes
• To output as a csv, type tasklist /FO csv
• To save the output of the command line to a file, add > filename.csv to the end of the command; for example, tasklist /FO csv > "%userprofile%\desktop\tasks.csv".

For full documentation on the various options for what to output, type tasklist /? into the command prompt.

One line in CMD

Replace <username> to your user name and run in cmd:

tasklist /v /FO csv > "C:\Users\<username>\Documents\tasks.csv"

For more documentation info go here:

https://docs.microsoft.com/en-us/windows-server/administration/windows-commands/tasklist