Have a fast computer should always be the goal. Computers run their fastest when the operating system is first installed and the computer registry and the hard drive are both fresh. The registry is a very large complex data base for all the software and hardware settings. As programs are installed, configured, and removed the registry can become corrupted from all these changes and you begin to notice that boot times are longer as the registry is looking for files that are no longer installed. Also in time the hard drive gets fragmented with all the files being written and deleted leaving many holes that are never filled
with exactly the same size files. This causes files to spill over to other tracks which makes the read write head work harder trying to read these fragmented files. To keep your computer running at its optimum a fresh install with a newly formatted hard drive can make a big improvement. I do this daily with a lab of 35 computers and it only takes me about 10 minutes. My students are always remarking about how fast the lab computers perform compared to other computers they use both at school and at home. Since my students are studying computer repair and maintenance they have complete admin rights and they can modify and change any setting on these computers. So with 6 classes using these computers each day they get quit a work out and need some daily maintenance. I use several Open Source (free) partitioning and imaging programs to maintain these computers and teach these skills to my students. I have produced several Computer Repair Training YouTube videos and many articles that are available if you are interested.
Slow Computer is a website where you might find some helpful information.
Very insightful post. I am going to link to it in my new blog.