Which optimizer software is very reputable and tested?

If you surf the Web, you stumble upon a bunch of programs claiming to optimize and speed up your Windows and promising to deliver whopping results by speeding up your PC by 400%.

A real cancer. The emphatic wording of these websites should already raise a red flag for you.

In the best-case scenario, these programs are crapware/adware, in the worst case, downright malware/spyware.

Keep off them!!! The fewer third-party software you install in Windows, the better.

These programs often end up causing harm, instead of solving your problem, and sometimes mess up your OS so badly that you have to re-install from scratch.

The best optimizer is, IMHO, UPCleaner - Free pc optimizer, which is very reputable and tested.

You can also used Comodo System Utilities and Glary Utilities, very decent pieces of software in this category.

Numerous guys keep posting answers around sponsoring either program because they are, IMHO, often paid for by the producer of that software, so I wouldn't trust those answers (unless they sponsor a reputable product).

If your Windows is very messed up, because of numerous installs and uninstalls, or because you have an older version (Vista, XP, or earlier) and/or insufficient RAM/storage space, cleaners are no use, so do yourself a favor and don't waste your time on them.

If you run a 32-bit version with 2 GB RAM, or a 64-bit version with 4 GB, no cleaner will speed up your computer, because you need more RAM.

Re-install everything from scratch, upgrade to a newer version, or (yet better) switch to Linux.