There are a number of miscellaneous things that can be done to keep a system operating in an efficient manner. This can be as simple as giving a machine a good clean, to replacing an old outdated machine with the latest model, and several options in between.
There is also the matter of security. Do you have good virus protection and a firewall?
Note: The most valuable part of your system is the data stored on it
Do you have a machine that is getting a bit slow and tired ?
There are a number of things that can be done to get the machine running to its potential. Some of the actions can be done by the untrained user, others can be done by an engineer quite quickly. So before going through the expense and hassle of replacing an old machine check if there is anything that can be done first. Some of the things that maybe required are detailed below :-


A lot of the standard maintenence is built into the Windows operating system such as the disc scan tool and the defrag tool, other tools are available to download from the Internet. Care should be taken when downloading tools from the net ("Free download" does NOT always mean a "free to use" product).
The frequency of disc maintenence is dependent on the use of the machine (a machine that is used a lot for saving documents and other files will need to be checked more often than a machine that is used only for reading files). I would suggest that defragging should be done at least monthly (at a time when the machine is not being used).
To protect your system it is essential to have some form of anti-virus program (unless your system is totally isolated). Anti-virus programs come in many forms there are those that are commercially available and have many extra features (some of these can be useful, some can be annoying), there are also a number of free programs that can protect your system from the most common attacks. Which one to choose would depend on your system (some of the free versions are restricted to home users only, others may be restricted to a small number of machines (usually less than 5 machines)). Note: It is well known that "Windows" is the most often attacked OS (Operating System), but Unix and Mac systems can be vulnerable to attack (or may just spread a virus without actually being affected).
Anti virus programs need to be constantly kept up to date. This is normally done automatically but may occasionally require a licence renewal. A Virus scan should ideally be performed at least once a week (more often if you use the internet frequently).

File Organisation

The organisation of your files is mostly a matter of personal preference, in the same way as organising paper files in a filing cabinet. Although a computer will over time collect a number of "junk files", such as temporary files left over from installations, old backup files, temporary internet files, and other stuff of a simular nature. These can eventually add up and in some extreme cases overload the hard drive. most of these files can be deleted easily. The popular internet browsers such as "Internet Explorer", "Mozilla Firefox", "Opera" and "Google Chrome" have built in cache removal tools. The temporary files left over from an installation will, in a Windows OS, be in a folder named "Temp" and located on your main drive (normally drive "C:"), on a unix system it is normally found at "/tmp". Microsoft Office produces back-up files which are marked with the attribute "hidden" and can be recognised as they start the file name with " ~$ " followed by the file name of the saved document.
Backup & Archive
Backups of your data should be done onto a removable media or portable hard drive and kept in a secure location (preferably in a different building) in case of fire, flood or theft. Backups are made to prevent the loss of critical data in case of emergency.
Archiving can be done in several ways, it may just be a case of putting all files of a certain age into a folder and copying them to a CD or DVD, and filing them away somewhere for future reference. You may wish to archive parts of a database, or compress the old files into a "zip" or "rar" file.
Program Installation
These days installing a program is often a simple operation most windows programs have their own installers (some Unix programs also have installers either ".deb" or ".rpm" dependent on the system)
Obsolete program removal
The removal of obsolete programs is NOT a case of deleting their containing folder. For example: You used to use a program called "MYUndies98" that edited drawings, but you have bought a new program that does the same job quicker and have more features called "NotMyUndies2013". You look in the "Program Files" folder and find a file named "MyUndies98". DO NOT just delete this folder (it will most likely cause more problems than it solves) Always "Uninstall" the program via the "Add/Remove Program" facility in Windows, (if possible).

Hardware Upgrade

There will come a time when your hard drive is nearly full or your machine slows down or stops when using certain programs. This is the time to consider upgrading. Adding an extra hard drive, increasing the size of your hard drives or increasing the memory capacity can be the answer and may extend the life of your machine(s). You may even be at a stage where you are considering buying a new machine. What is the best machine for my business? How do I transfer my data from my old machine to the new one? Can I still use my old programs? These are some of the questions which need to be answered before spending money on a new machine. This is where asking a professional for advice is preferable to avoid costly mistakes.

Drastic Measures

There are times when the only option is to start from scratch, and extreme measures need to be used, (these should only be used after all other options have been exhausted).
Before embarking on any of the extreme procedures make sure you have a backup copy of all critical data (All data on the disc will be lost).