One of the most common problems that people report to me is that their PC or laptop is running very slowly. There are a number of reasons why this happens. When your PC was new, it would have only had programs on it that were installed by the manufacturer; typically Windows and several 'value added' programs depending on which brand of PC you purchased. Over time, you will undoubtedly download and install other programs of your choosing. In addition, Microsoft will issue updates to whichever version of Windows is running on your PC.
The updates to Windows and some other programs are essential and help to keep you safe on the internet.
Other programs, such as browser extensions and toolbars are usually a hindrance and just clutter up your PC and slow it down.
Usually, when you download 'free' software, in order that the vendor of that software can supply it free to you but still make money, it will allow by default, other company's software to be bundled in with what you have requested. It is this additional software that is usually unwanted, intrusive and often quite tricky to get rid of once you've got it.
Even the aforementioned 'value added' software included at the time your PC was built can contribute to your PC running more slowly than it might otherwise do. Often it provides no benefit whatsoever.
I specialise in removing what is known in the industry is 'crapware' from PCs and returning it to something approaching the state it was in when you first got it.
I should point out that whilst significant improvements in performance can often be achieved, an aging PC will never run as fast as it did when new because of essential updates to Windows that accrue over time, and other programs which you have added yourself that you actually do want and need.
Sometimes, I will recommend adding more memory to your PC or laptop if it is possible and if I feel it can be of benefit.