The most valuable question in all of troubleshooting is also the shortest: slow everywhere, or slow only here? A PC-wide fault and an app fault share no fixes at all, yet people reinstall Windows for what turns out to be one corrupt spreadsheet. This page is the scope test - three small trials that separate the app, the file and the machine before a single setting is touched.
Start by believing the user's sentence precisely. My PC is slow often means my Tally is slow or Chrome is slow - their whole working world is one program, so its name and the PC's name merge. Test the sentence: open two or three other programs and do real work in them. If they fly, the PC is probably innocent and your suspect list just shrank from the whole machine to one application - and its files.
Open the exact slow file in a different program that can read it - the spreadsheet in another office suite, the photo in another viewer, the PDF in the browser. If the file opens instantly there, the file's data can be read at full speed: the disk, the PC and the file's content are all cleared, and the original app stands alone accused.
If no second app exists for that format, a fresh file of the same type in a simple tool gives a weaker version of the same evidence.
Now open the accused app with a small, new, known-good file - a blank document, a tiny spreadsheet. If it opens in two seconds and works normally, the app itself is healthy and suspicion moves to the file. If even a blank file crawls, the app's own machinery - its profile, add-ins, cache or update state - is where the slowness lives.
Note both timings in your symptom line. Two small numbers from two trials do more diagnostic work than an hour of forum reading.
Each family of apps has its known hiding places, and the scope test points at them:
Reproduce the freeze with Task Manager open. If only that one process pins the CPU or waits on disk while the rest of the system idles, the scope verdict is confirmed by instruments, not just trials. If everything pins - CPU, disk, the lot - the app was merely the loudest victim of a PC-wide fault, and the four-meter method from the core page takes over.
That single glance during a real freeze prevents the most expensive mistake in this territory: reinstalling or replacing the PC for an app, or reinstalling the app for a dying disk it happened to expose.
The video runs these three trials in minutes - watch how fast a whole-machine mystery shrinks to one file.
Watch Full VideoAlmost certainly not. Scope it: try another browser on the same sites, then Chrome with a fresh profile. A bad extension or one heavy tab explains most browser-only slowness, and the rest of your PC flying is itself evidence the hardware is healthy.
The file carries the fault - its size, external links, embedded objects or formatting damage. The app is proven healthy by the other files, and the PC by everything else. Fix the file, not the machine.
Reinstalling is a fix, and fixes without a scope verdict are gambles - you will not know if it helped, and if the fault was the file or the disk, the reinstall only wasted an hour. The three trials take five minutes and tell you which reinstall, if any, is even a candidate.