When you first buy a computer from a shop it will be fast because you were sold a computer with the bare minimum only installed on it - Windows 10 and Microsoft Office for example. It is not heavily installed with Updated Security files (Security Updates) and Patches (Fixed/Improved/Updated Windows 10 files and program files) because the shop can not do this. Once you have bought a computer you have to be the one to register Windows 10 with Microsoft and therefore it is you who has to install any additional Security Updates and Patches for that computer and Windows 10.
If it took the shop 2 Months to sell the computer for example that means the computer is already 2 months behind with the updates - Many new security updates, virus updates and program updates would have been released in this time. And maybe some software updates for the computer's hardware as well. All these updates are required to keep the computer up-to-date, and more importantly Windows 10 up-to-date and protected against attack from Viruses, Hackers and so on.
What this means is without the updates you have a fast, but vulnerable (open to attack), computer. With the updates the computer becomes slower and slower due to Windows 10 being given more security tasks (jobs) to do, which means more memory and resources are required, which in turn means the hardware might become slower (more modem/internet data coming down the telephone line, for example, means more data that has to be translated/organised).
You install an Anti-Virus program to protect the computer from Viruses (files that are, normally, downloaded onto your hard drive and then launched to damage certain files). You then install a program to block Pop-up windows (Windows that appear suddenly without your consent. Usually with Advertisements on them). You then install a program to stop Hackers (people who try and steal information from your computer via an Internet connection). And finally, you install a program to stop SpyWare (software that monitors/collects information about your activities on the computer).
Unfortunately, in todays age, these four types of program are needed to protect the computer; even if they come as part of an overall Internet Security package. If you do not install them the computer's security is at risk and if you do install them the computer uses up more memory and other resources, as well as having more tasks to do. This is because each program is constantly monitoring the computer for attacks. The information they need about the different kinds of attack are usually stored inside a file that has to be updated regularly and checked against in order to prevent/stop a specific kind of attack. When an attack has been identified the protection program still has to monitor for other potential attacks whilst taking care of the identified attack. And if a window tries to pop-up the pop-up blocker program has to destroy that window before it has chance to appear. All this monitoring is slowing the computer down.
The same applies to the Internet. It becomes slow when you have ten website pages open, as opposed to one website page open, because Internet Explorer is having to do ten tasks instead of one. Those tasks include saving history files (see The Hard Drive section) for each website, checking to see if you are still connected to the internet, managing uploads/downloads to/from each website and so on.
An anti-virus program uses a Virus Definition file, which is a list of all known viruses to the present day and instructions on how to identify and remove them. As a new virus is unleashed it is given a name and its Identify And Remove instructions are added to the virus definition file. When the anti-virus program starts it copies the identify and remove instructions from the virus definition file into memory, so it can quickly identify and remove a known virus. Memory is faster than a File at feeding the CPU instructions, so it is ideal for the anti-virus program to use memory. The downside of this is that anti-virus programs, and other programs that need updated files, use a lot of memory and other resources in order to protect the computer. This ultimately means a slower computer.
Having too many, unwanted/unneeded/unused, programs installed on the computer is a bad thing. Regardless if they were already installed when you got the computer or if they were installed by someone afterwards does not matter. Either way they are probably taking up too much hard drive space and/or using up too much memory and other resources. If this is the case you should have them uninstalled. Below are examples of such programs. Many of them will be Sluggish At Times when your broadband in running at a slow speed, for whatever reason(s), in conjunction with your computer having too many other tasks to perform.
|Software||Resources?||Response?||Why Is It Installed?||Extras Installed?|
|Adobe Acrobat Reader||Harddrive||Sluggish At Times||To Read .PDF formatted files||Software Updater|
|Adobe Flash and Shockwave players||Memory||Sluggish At Times||To display Flash Media/Animations on a webpage|
|Apple - ITunes (IPod) Media Software||Harddrive and Memory||Sluggish At Times||To communicate with an IPod||Software Updater|
|Apple - QuickTime Media Player||Harddrive and Memory||Sluggish At Times||Media Player for .mov formatted files||Software Updater|
|Google Desktop||Harddrive and Memory||Heavy On Resources||Helps make searching for your indexed files easier||Software Updater|
|Google Picasa||Harddrive and Memory||Can Be Slow||Helps you to organize, edit, and share your photos||Software Updater|
|RealPlayer||Memory||Sluggish At Times||Media Player for .rm and .ram formatted files||Software Updater|
|Sun JAVA||Light on resources||Fine||Needed by Mobile Phone software, Limewire (Music
Download) software and OpenOffice software
|Microsoft SilverLight||Memory||Sluggish At Times||As an alternative or addition to Adobe Flash Player|
Sometimes you might need to install an updated program because it improves on the previous one (such as DirectX and Media Player) which improve graphics and sound respectively. On the other hand it is sometimes unwise to install an updated program. For example: Do not install the latest Media Player just because everyone else has or because it has a couple of minor updates/features added to it that you might never use. Go to an Internet Cafe instead and ask them what they think.
You can always download and test the media player on one of their computers. That way, if you do not like it or feel it would not be worth putting on your computer no harm will have been done to your computer. Also, do not install different types of the same software if you only need one type. Companies are to blame for this kind of thing - One company might prefer the already installed Microsoft's media player while another company might prefer to install Real's media player (RealPlayer). So you end up with two media players installed on the computer that do roughly the same thing.
When you add all this up - Many programs writing/reading files to/from the hard drive at the same time (giving the hard more tasks), many programs waiting for system resources such as Memory to become available (because of memory shortage), programs monitoring the Internet (slowing the internet and the computer down) waiting for bad things to happen and having many programs running at the same time (so many tasks) - it is no wonder the computer slows down.
If you were given that many tasks (chores) you would complain that you are only human and only have one pair of hands. A computer is only a machine. It complains in different ways by slowing down and occasionally crashing/freezing because you were giving it too many tasks. If you follow the advise given so far you should end up with a comfortable computer - one that runs smoothly, even if it is not as fast as when you first bought it. For more reading see the Disable Unwanted Startup Programs section.