If your drivers are working properly and you have no reason to think any of them are causing problems, or if you think a newer version might be faster, there is no reason to update them.
Personally I've had more problems occur when I update my drivers; except in a few rare instances where I noticed specific issues with an older version.
Either way- there is no reason to use a program to search for drivers. a tiny bit of education about your hardware (video card, sound card, Etc) and you'll be able to simply go to the manufacturer's site and download the newest versions.
For example; my Video card, is a "BFG Tech Geforce 9800GT. If I wanted to update the drivers (for whatever reason) I would first go to bfgtech.com and see if there are new versions there. (actually, this is what I had to do since the driver cd didn't work for some reason)
If not, The card uses a NVidia chipset, and NVidia releases "reference" drivers that work with most of their Graphics processors.
my motherboard is made my GIGABYTE, so if for some reason I am unhappy with the version of the drivers I installed, I would go there and find it.
The main reason people turn to these sorts of programs is actually simply laziness; it's good to automate things, but IMO automating Driver updating is like registry cleaning; it can often cause more problems then it solves. To make matters worse, a good number of people believe that keeping drivers "up to date" is part of regular PC maintenance. It isn't- The drivers perform a critical function, and if they are working there is no cause for concern; unless there is a specific issue that may be solved by a driver update; for example, speaking again of my video card; when I played "crysis" on any graphics setting, it worked flawlessly, but after around 20 to 30 minutes, inexplicably crashed. Vista was able to determine that the driver was the culprit. After a week or so I relented and discovered that the newest version was only a few days old, upon installation I found crysis worked perfectly fine (as long as I kept it one notch below the highest settings). In this case there was an issue with the driver and I attempted to solve it with a new version, and (miracle of miracles) I was partially successful.
Not every "driver-search" program is a scam, but they are a waste of hard-earned cash and additionally can cause problems in the long run; best solution is the download new drivers from the manufacturer's site, and only when you feel it is necessary.
Also, I have witnessed instances where programs of this nature don't actually update drivers; they download the "updates" but every single one is the same size and exactly the same. Turns out that some of these "driver search" programs are a front-end for a trojan downloader.
