Sometimes it's the mouse
If your computer is lagging and behaving slowly, there is a possibility the problem could be your mouse or keyboard.
If your computer is lagging and behaving slowly, there is a possibility the problem could be your mouse or keyboard. When input devices do not work properly, sometimes button clicks may take a while to register, or there may be intermittent disconnects that can cause cursors to move in a jerky manner. At times, the behaviors may be similar to those when systems experience slowdowns, which may cause people to assume their systems are running slowly when in fact their mice are malfunctioning.
If you have a wireless mouse and keyboard, be sure to regularly check the battery level because low batteries can easily cause this kind of behavior (though many mouse systems have onboard or onscreen indicators of battery levels).
Mice and keyboard problems can develop over time, and many times we take it for granted that the input devices will be working properly so we do not notice them. After years of use, mice and keyboards can accumulate dirt under buttons and in scroll wheels, the buttons can become loose or wear out, and the wires in the cord can eventually break from being repeatedly moved around. This can all lead to seemingly slow system behavior.
Not only can such problems lead to poor interface performance, but if the device is not communicating with the computer properly or is repeatedly initializing because of constant disconnects, then it could also cause other peripheral devices to lag.
If you are experiencing problems with a slow OS interface, then you might try changing your mouse and keyboard with a spare one to see if there are any performance differences. Any USB keyboard and mouse should do, but when troubleshooting be sure to disconnect all other USB devices since malfunctions in them could also be what's leading to the problems. For wireless mice, try changing the channel if possible, or try unpairing and re-pairing the device again.
Mouse and keyboard recommendations
If you are going to purchase a new mouse and keyboard, there is no way to recommend input devices to someone. A mouse that is perfect for one person may have an irritating fit or feel for another. There are also several workflow considerations such as wireless or wired, notebook- or desktop-size, portability, and the various button types and placements.
In most cases the mouse comes down to personal fit and feel, however, one recommendation I can make is if you have a little more cash to spend then try a gaming mouse. These mice have the same variations as others in terms of size and features, but generally have a few more options that can make everyday tasks feel much smoother. Their high DPI and sampling rate settings can also help in creative design and other tasks, so even if you do not regularly use your computer for gaming you can still benefit from the higher performance of the gaming input devices.
To a degree what is called a "gaming mouse" can sometimes be just advertising hype, so overall the idea is to look for smooth and crisp-clicking buttons, and a nice weight to the scroll wheel, which can sometimes make a world of difference. Many gaming mice also have grip pads and other rubberized coatings that make handling easier.
These same recommendations also apply to keyboards, with some having features such as backlights and extra function keys, and others being slimmer and low profile like Apple's aluminum keyboard.
Do you have a favorite mouse and keyboard combination? Let us know in the comments.