Update Drivers: (Use any of these with extreme caution, all not by the vendor of your computer can cause you grief)

Drivers are small programs that help hardware communicate with the software.  When you attach a new piece of hardware to your system, you may run a program to install the drivers or windows may just recognize you have installed new hardware and will go on the internet to get the drivers.  Over time these drivers become out of date.  Running out of date drivers is not a security issue but it may cause some performance problems and occasionally even lead to crashes.  Some drivers like for video cards seem to be updated all the time, even weekly, others rarely.  I suspect the frequent updates to video drivers is only an issue for those playing leading edge video games. Windows update which you are bound to be running anyway updates some drivers safely.
I am now of the opinion that all other programs to update drivers, unless it is from something like the maker of your video card, are programs to use with extreme caution.   It is only a matter of time before your system gets messed up and you will have to go back to a previous configuration.  I think you should save the system configuration before updating drivers so you can use the option to go back to a previous restore point.  I would just update drivers about once a year so you will need to tell your program to not automatically scan for problems. Outdated drivers usually do not cause any sort of problem.  I have had 10 or more outdated drivers and not noticed no change when I updated all.

By far, the best driver update procedures are supplied by the vender of your computer.  I have a couple of Dells and Dell has a not particularly user friendly system.  If you have a dell look for a program in your Dell folder of programs called Dell update.  Run it to take care of the easy problems.  Now go to Dell.com, select Support then drivers and downloads.  Now select Detect PC or enter service tag.  Then Select "detect drivers"  Select download and install for any it finds.  It also lists a bunch of other drivers down below.  They are probably ones already installed. Lenovo has a program called "Lenovo Vantage" which is simaler.  Other manufactures probably have a similar system.

AVG Driver Updater will scan for free but costs $29.99 for one device for a year with discounts for multiple devices and years.     (Driver Update is a free version of AVG Driver updater, I have not figured out the differences yet.)

DriverMax (My favorite) from CNET's Download.com  or DriverMax.com. The program has a free version that is a little awkward to use and can only download 2 drivers per day in the free mode. The paid version costs $34.90 for a 1 year license and can be run on up to 20 computers.  During installation it wants to install a bunch of other programs so select custom install and deselect the extra programs. An older computer I was working on had 26 out of date drivers.  When you first run the program it identifies drivers that need updating.  The paid version is very strait forward but less so for the free one. On the free one, You then select one and click on "Download" then "Free Download".  Once it is downloaded, click "View" then Install or if multiple drivers have been found, "Select all" then "Install".  It may show you more than one.  Some may already be installed so look closely.  Only install the ones that say "Ready to Install".  The world will not end if you install the others but you will installing an identical driver to the one that is already there. It will then ask you to agree to the license agreements of the company how makes the drivers, click "I agree" It then asks if you want to create a restore paint, definitely say yes. It will then start the download. The screen my blink black but do not panic.   When the installation is done, it will tell you and may require a reboot.  Click "OK". To do the next driver that needs installing, click on  the back arrow in the upper left then "Scan for updates now"
If something went wrong and you wish to undo the update, first right down what you can remember about the name of the update that messed things up before you forget. Then select "Driver backup and restore" then "Restore point". This is the regular windows restore system.  Pick a date and time when things were OK and click "Restore"   Remember to not attempt to install the problem driver again.  Driver max defaults to continue to run in the background and worn you whenever if finds out of date drivers.  This might not be a desirable attribute on a computer of a novice, the warning messages would be confusing.  To stop it from automatically scanning, select "Settings" then "Application Settings"

I would only recomend useing it with a computer that does not have a company behind it such as home built ones.  The risk is just too grate otherwise.

Iolo System Mechanic does lots of things to speed up your PC, one of which used to be checking for outdated drivers. Click HERE to see a full description.

DriverMax found twice as many drivers that needed updating compared to AVG Driver updater.  At least part of this higher count was due to false positives.  It updates a driver with the version already there. This is harmless.  System Mechanic has the advantage that it does a lot of additional things so there is merit in using it.  It may not find as many but it gets most of them and is more versatile.  AVG found a third more drivers to check on my system compared to DriverMax but DriverMax found 4 that needed updating that AVG did not find.  When I tried to see if the updates were really required by going to the vender's web site in 2 of them that I could identify, I could not make sense of the suggested updates.  I am not certain what this means other than be a little suspicious of all driver updaters.  I did the updates and everything works fine, just like before I updated.

DriverMax is what I am currently using as my main driver updater but keep in mind with any of them, aside from my very underpowered newest computer, it has never made a detectible difference.

Driver updaters to avoid: Driver Booster 2 and SlimDrivers both caused me serious problems.  In one case I had to restore my computer from my backup and the other I had to use the option to go back to a previous version of my system so I recommend avoiding both.

Recommendation: Run Driver Max without paying for anything.  You will then see how many drivers need updating. 20 is not a large number for a computer 5 or more years old.  When you see the number, you can decide whether you want to struggle through the free version or not.  Note that once you update all, you will have more needing updating at a rate around 1 or 2 a month.  Obviously these are not too critical, typically video drivers for the latest games.

Do not expect significant help by updating your drivers.  This is typically a feel good exercise like running a registry cleaner.  I have updated drivers on about 6 machines and only noticed an improvement on one, a very under powered computer about 2 years old.  If you run things like high performance recently released games, the story could be different.  Video drivers seem to be updated all the time and I suspect it is to keep up with new games.