guys pls help my budget notebook takes forever to become usable after opening the browser... task Manager shows this:

Disk 0 (C:) Active time 100%
Not responding
Disk at 100%, and teh response time is huge. Clicking anything takes ages. After 15 or 20 minutes it calms down. Its a few years old with a regular hard drive. Is smth wrong, or is this just how it is now? Im not suree if this is normal for an older budget notebook or a sign that smth is about to fail. Upgrading is possible, but Id like to understand the cause first.