The term upgrade refers to the replacement of a product with a newer version of the same product. It is most often used in and , generally meaning a replacement of , or with a newer or better version, in order to bring the system up to date or to improve its characteristics. Contrast and . See also .
Common hardware upgrades include (for example) installing additional memory (), adding larger , replacing microprocessor cards or , and installing new versions of software. Many other upgrades are often possible as well.
Common software upgrades include changing the version of an , of an , of an anti-virus program, or of various other tools.
Common firmware upgrades include the updating of the control menus, the dashboard, or the non-volatile flash memory that contains the for a device.
Users can often download software and firmware upgrades from the . Often the download is a —it does not contain the new version of the software in its entirety, just the changes that need to be made. Software patches usually aim to improve functionality or solve problems with . Rushed patches can cause more harm then good and are therefore sometimes regarded with scepticism for a short time after release (see "Risks"). Patches are generally free.
A software or firmware upgrade can be major or minor and the code-number increases accordingly. A major upgrade will change the version number, whereas a minor update will often append a ".01", ".02", ".03", etc. For example, "version 10.03" might designate the third minor upgrade of version 10. In , the minor upgrades (or updates) are generally free, but the major versions must be purchased. See also: .
When one replaces a product made by one supplier with a product made by a different supplier, one carries out a competitive upgrade.
Although developers produce upgrades in order to improve a product, there are risks involved—including the possibility that the upgrade will worsen the product.
Upgrades of hardware involve a risk that new hardware will not be compatible with other pieces of hardware in a system. For example, an upgrade of RAM may not be compatible with existing RAM in a computer. Other hardware components may not be compatible after either an upgrade or downgrade, due to the non-availability of compatible for the hardware with a specific . Conversely, there is the same risk of non-compatibility when software is upgraded or downgraded for previously functioning hardware to no longer function.
Upgrades of software introduce the risk that the new version (or patch) will contain a , causing the program to malfunction in some way or not to function at all. For example, in October 2005, a glitch in a software upgrade caused trading on the to shut down for most of the day. Similar gaffes have occurred: from important government systems to on the internet.
Upgrades can also worsen a product subjectively. A user may prefer an older version even if a newer version functions perfectly as designed.