If cleaning RAM did nothing lasting, that result is itself a diagnosis: either memory was never your root problem, or it is a hardware problem that software cannot solve. These are the checks and fixes that actually move the needle.
A cleaner is a ten-second experiment, and a failed experiment is information. Work down this page in order: find what is really consuming the machine, restart it the way that actually counts, remove the load you never use, and measure your physical RAM honestly. One of these is your real fix.
Open Task Manager and sort by CPU, then by Memory, then by Disk - three different bottlenecks wearing the same "slow PC" costume. An app pinned at high CPU is not a RAM problem and no cleaner will touch it. A disk stuck at 100% on an old hard drive is a storage problem. Only a memory column where Available sits near zero while the PC swaps is a true memory problem - and even then, note which process owns the growth before acting.
With Fast Startup enabled (the Windows default), choosing Shut down hibernates the kernel instead of ending the session - so a PC "shut down" every night can carry the same leaks and tired drivers for months. Use Restart, which always performs a full fresh boot, or run shutdown /r /t 0 for an immediate full restart. If your "slow PC" has not had a true restart in weeks, this single step is the most likely cure on this page.
Open Task Manager > Startup apps and disable what you do not need from the first minute of the day - chat apps, game launchers, updaters, vendor helpers. They can all still be opened manually when wanted. Unlike a RAM clean, this fix is permanent: less load at sign-in, less resident memory, less background CPU, every single day. It is the closest thing to free speed that Windows offers.
Guessing helps nobody. Run this in PowerShell to see every installed stick - which slots are filled, capacity and rated speed:
Get-CimInstance Win32_PhysicalMemory | Select-Object BankLabel, Capacity, Speed
Capacity is shown in bytes. Two discoveries matter: an empty slot (the cheapest upgrade there is) and a PC trying to do modern work on 4 GB (no software setting will save it). Also confirm both sticks are seen - a stick that has silently dropped out looks exactly like "my PC got slow this year".
If your committed memory regularly exceeds your physical RAM during normal work, the diagnosis is arithmetic, not software: you need more RAM, matched to the type and speed your board already uses. It is the one upgrade that ends the problem instead of postponing it. One honest neighbour-note: if the same old machine still runs a spinning hard disk, an SSD often improves daily feel even more than RAM - do the storage upgrade first on HDD machines, then re-measure before spending twice.
Every few years the tip returns: disable the page file to "force" Windows to use RAM. Do not. The page file is the safety valve that keeps a memory spike from crashing your apps, and Windows manages its size well on System managed. Disabling it turns a slow moment into a closed program - or a blue screen. If a guide's big idea is removing the safety net, the guide is the problem.
The complete knowledge and full walkthrough are in the video - the tool on a real PC, every option shown live.
Watch Full VideoAlmost certainly not. High usage with most of it in standby cache is Windows working as designed. Judge by Available memory and by how the PC responds, not by the headline percentage.
Whenever it starts feeling tired, and at least every few days for machines that run constantly. Restart (not shutdown, with Fast Startup on) clears leaks, resets drivers and finishes pending updates in one move.
Only when memory is the bottleneck - committed demand regularly above physical RAM. If the limit is a dying hard disk or a weak CPU, RAM will not rescue it. Measure first with Task Manager during your heaviest normal work, then spend.