A booster cannot give your PC hardware it does not have. What it can do is stop the machine from spending capacity elsewhere while you play. Here is the whole honest list.
Five settings, all of them documented by Microsoft, and none of them magic. Together they matter most on a machine that is doing several things at once — which is the normal state of a PC with a browser open.
On a quiet machine with nothing else running, expect very little. That is not a failure of the tool; there was nothing to reclaim.
Many boosters freeze background processes outright. The call they use is an undocumented one from ntdll, and it is the same call at the heart of the technique attackers use to freeze security software. An unsigned program that makes it is asking to be flagged, and deservedly so.
It is also barely worth it. The measurable difference between “this process is suspended” and “this process is at Below Normal with low memory priority” is small, and the second cannot hang a program that owned a lock when you froze it. Rain Cleaner never suspends and never kills anything. It only steps things down.
A game client was run against a browser with a dozen tabs and four CPU load generators, and the game's own CPU share was measured before and after.
Before the boost the game was getting 16.6 percent of the CPU — it was starving. After, 25.1 percent: about half as much again, plus 206 MB of memory handed back. Nothing was killed to achieve it; thirteen browser processes were stepped down and every one of them was still running afterwards.
It cannot add cores, memory or a better graphics card, and it cannot make a game engine faster than it is. If a game is limited by the GPU — which most modern games are — reordering CPU priorities changes almost nothing.
It also cannot fix a hot laptop. A machine that throttles because it cannot get rid of heat needs the vents cleaned and the paste replaced, and no registry value will substitute for either.
Every setting a booster touches is a setting your machine keeps after the game closes. A power plan left on High performance drains a laptop battery for days afterwards, and a priority left raised is a background program that never gets its turn again.
So the session is written to disk before the first change is made, not after. If the machine loses power in the middle of a game, the next launch finds that record and puts everything back. Closing the window puts it back too. The measured proof is boring and that is the point: Balanced, then High performance, then Balanced again, with the registry values back where they started.
Last updated: 2026-08-28
On a machine with plenty of headroom, close to none. On a machine that is busy — a browser with many tabs, a chat client, an update running — the difference is real, because the game stops competing for a share it was losing.
Game Mode does part of it: it limits some background work while a game has focus. It does not change the power plan, the GPU preference or the memory priority of everything else.
It changes Windows settings, not the game and not its memory. Nothing here is injected into a running process, so anti-cheat has nothing to object to.
The safe order — Windows Update, then the manufacturer, never a driver pack.
Category by category — what you get back, and what you quietly give up.
What “free” should mean, and how to check a cleaner before installing it.
Free, no account, no subscription. Windows 10 and 11.