Find a drive you can sacrifice. Nuke it. Scrape it down to bare metal. Then load it with your favorite OS. Let it get all the updates first, before you do anything else.
Next, install the applications you absolutely MUST have: browser, word processor, email. That. Next, list the applications you need to do the job you're about to start. ONLY those applications. Find them, find the info you need for them, find the data you're working on, and load ONLY those things.
Set everything else aside; work. When you finish, repeat with the next set.