Open Task Manager → Processes, sort by Memory and close or fix the heaviest apps (often browsers). Disable unneeded startup apps, restart to clear leaks, and make sure the page file is system-managed. If you regularly run out, add RAM.

The short explanation

Windows keeps recently used data in memory ('standby' cache) and releases it instantly when apps need it, so 'in use' is the number to watch. Browsers with many tabs, games, VMs (Vmmem) and memory leaks in drivers or apps are the usual heavy users.

Signs of the problem

  • Memory at 80%+ in Task Manager.
  • Slowdowns and 'low on memory' warnings.
  • Apps closing unexpectedly.

Common causes

  • Many browser tabs and extensions.
  • Background and startup apps.
  • Memory leaks in apps or drivers.
  • Too little RAM for the workload.

Fixes to try, in order

  1. Find heavy appsTask Manager → Processes → sort by Memory.
  2. Tame the browserClose tabs; enable Memory Saver / Sleeping tabs.
  3. Trim startup appsSettings → Apps → Startup.
  4. RestartClears leaks and temporary allocations.
  5. Check the page fileKeep virtual memory on Automatically manage.
  6. Add RAMIf memory use stays high doing normal work, more RAM is the fix.
How to confirm the fix: Memory in use drops and the PC stays responsive.

Prevent it from coming back

Limit startup apps and extensions; restart regularly.