To second Pauli's comment, it's good advice for both drivers and Windows updates. If the publisher states what the update is supposed to fix, read that, then apply your own decision based on knowledge. Windows updates and driver updates are in two different categories. Windows updates definitely apply to what is on your computer but may not be relevant, while driver updates may not apply to what is on your computer.
Windows updates: Microsoft puts out two kinds of updates--those for security and those to fix problems or improve performance. You generally want to install anything related to security. For the other type, you should use some judgement. Win 7 may be reaching the point where there is more code in patches than in the original OS. You can't patch anything to that extent without the patches creating new problems. In fact we just saw this with Microsoft issuing patches to fix the patches after the recent massive update distribution.
If you read the description of each update, you are likely to find that the majority of them aren't relevant to you. They fix problems running software you don't use, or problems on a network and your computer is a standalone, or problems with language packages that don't apply to you, or to improve the transition from Win 7 to Win 8 and you don't intend to go there. On my computer, Microsoft's own Outlook 2007 became incompatible with Win 7 as currently patched. I used to install anything that Microsoft sent as an update. Now I generally don't install any non-security update that is irrelevant to my usage.
Driver Updates: The retail version of hardware is often different from what computer manufacturers put in your computer. The motherboard manufacturers will incorporate the chip set onto the motherboard and that never changes. What the device manufacturers sell retail may get improved/changed over time. The device manufacturer may update the driver to reflect changes in the retail version, to improve performance, or to fix problems running certain software. Bugs in the original code are generally found quickly, not years later. If you get a driver update from the computer manufacturer, it will be a version that works properly with the OEM hardware in your machine. Loading an "improved" driver from the device manufacturer often will not work properly with the OEM hardware.
If the OEM device on your computer is working properly, think twice about changing it. If you do, get the update from the computer manufacturer. If you just want to try an "improved" driver from the device manufacturer, think three times before you do it, and then test it thoroughly to ensure that you haven't introduced a problem you didn't previously have. If you are currently having problems that point to a corrupted driver, go to the right source (computer manufacturer or device manufacturer), for a replacement or updated driver.
As with Windows, if a new driver is released to fix a bug, make sure it applies to your hardware and that it is to fix something relevant to you. If it is OEM hardware and your computer is several years old, it is doubtful that the discovered bug applies to you and that you were never aware of the problem (if you weren't aware of it, it couldn't have been too serious of a problem). If it is to fix a problem running certain software and you don't use that software, there is no upside to changing it.
Pauli is right about not automatically installing every update or never changing anything that is working. It is important to be actively involved in maintaining your own computer. If you don't feel comfortable enough to "second guess" the experts pushing the updates to their own software, the safer alternative approach would probably be to install all recommended Windows updates and no driver updates unless something isn't working. Also, remember that in most cases, you can uninstall or roll back updates that cause problems or skip installing them until later if your computer is working.