As strange as it might seems, some softwares are faster than others to accomplish the same tasks.
Installing a previous version of your operating system can make your PC run faster. That is especially true for Windows because each new version brings more features and become slower. Windows versions before Windows XP are not recommanded since they are less secure and almost abandonned.
As the web is ubiquitous today, installing and using a faster web browser might be a very good trick. Most Windows users use Internet Explorer only because it is pre-installed in the PC and even ignore that alternatives exist. Internet Explorer is unfortunately a very bad choice since most other web browsers are free and really faster, why not benefit from this? Let's say that the better browsers in our opinion are Google Chrome and Firefox.
For other softwares that you might use, it's up to you to observe if performances are enough for you or if there is concurrent softwares that can be better and faster for you.