Pre-installed software (also known as bundled software or crapware ) is the software already installed and licensed on a computer or smartphone bought from an original equipment manufacturer (OEM).
Purchasing hardware and software together is cost-effective, and discounts are possible from OEMs on bulk orders. 
Pre-installed software commonly suffers from one or more of the following problems:
- It is usually licensed for use only on the computer on which it was pre-installed, and is not transferable to other computers.
- It is often functionally or time limited, in an effort to get the user to purchase the "full" version.
- It often does not come with any media, should the user need to reinstall it.
- It sometimes modifies or replaces the default browser or system settings, in an effort to target specific advertisements to the user; or may otherwise contain functionality the user might consider to be malware.
- It often consumes system resources, even if not actively being run by the user, adversely affecting system responsiveness and startup time.
- It is sometimes difficult or impossible for users to remove, such as via the standard uninstall utility provided by the system.
Often new PCs come with pre-installed software which the manufacturer was paid to include but is of dubious value to the purchaser. Such unwanted pre-installed software and advertisements are derogatorily called "craplets" (a portmanteau of crap and applet) and crapware. In January 2007, an unnamed executive spokesman for Microsoft expressed concern that the Windows Vista launch might be damaged by poorly designed, uncertified third-party applications installed by vendors — "We call them craplets." He stated that the antitrust case against Microsoft prevented the company from stopping the pre-installation of these programs by OEMs. Walter Mossberg, technology columnist for The Wall Street Journal, condemned "craplets" in two columns published in April 2007, and suggested several possible strategies for removing them. According to Ars Technica, most craplets are installed by OEMs who receive payment from the authors of the software. At the 2007 Consumer Electronics Show, Dell defended this practice, stating that it keeps costs down, and implying that systems might cost significantly more to the end user if these programs were not pre-installed.
Some system vendors and retailers will offer, for an additional charge, to remove unwanted pre-installed software from a newly purchased computer; retailers, in particular, will tout this service as a "performance improvement." In 2008, Sony Corporation announced a plan to charge end users US$50 for the service; Sony subsequently decided to drop the charge for this service and offer it for free after many users expressed outrage.
The practice is not limited to personal computers; mobile phones typically come with pre-loaded software provided by its respective provider; similarly to their PC equivalents, they are sometimes tied to premium services offered by the provider. The practice was extended to smartphones via Android devices, as carriers often bundle apps provided by themselves and third-party developers with the device and, furthermore, install them in such a way that they cannot be completely removed from the device without performing unsupported modifications. Some of these apps may run in the background, consuming battery life, and may also duplicate functionality already provided by the phone itself; for example, Verizon Wireless has bundled recent phones with a redundant text messaging app known as "Messages+" (which is set as the default SMS app in lieu of the stock messaging app or Google Hangouts), VZ Navigator (a subscription service redundant to the free Google Maps service).
Android 4.0 attempted to address these issues by allowing users to "disable" apps—which prevents them from running, and hides them from application listings. However, this does not remove them from the device entirely, consuming storage unless they are removed via irregular means. On its variant of the LG G3, bundled apps are not bundled with the device, but downloaded in the background upon activation; they are installed in such a way to allow certain apps to be removable. In April 2014, South Korea implemented new regulatory guidelines for the mobile phone industry, requiring non-essential apps bundled on a smartphone to be user-removable.
- Melanie Pinola (November 21, 2012). "Here's all the crapware that comes with new Windows 8 PCs". IT World. Retrieved 2013-01-24.
- Justin James (December 5, 2012). "Five apps for crapware cleanup". TechRepublic. Retrieved 2013-01-24.
- Jared Newman (Jan 15, 2013). "Lucrative Windows crapware market is exactly why we need app stores". PCWorld. Retrieved 2013-01-24.
- Fisher, Ken (2007-01-11). "$60 to keep crapware off of a Windows PC?". Ars Technica. Retrieved 2008-01-06.
- "Pre-installed on a new computer", a Microsoft article
- Khan, Saleem (2007-01-10). "'Craplets' could damage Vista launch: Microsoft exec". CBC News. Retrieved 2008-01-06.
- Mossberg, Walter S. (2007-04-05). "Using Even New PCs Is Ruined by a Tangle of Trial Programs, Ads". The Wall Street Journal. Retrieved 2008-01-06.
- Mossberg, Walter S. (2007-04-12). "Ways You Can Avoid Getting Junk Programs on Your New Computer". The Wall Street Journal. Retrieved 2008-01-06.
- Rob Beschizza (2008-03-21). "Breaking: Sony won't charge $50 to remove bloatware". Wired. Retrieved 2009-10-29.
- "LG G Vista (Verizon Wireless)". PC Magazine. Retrieved 22 October 2014.
- "Bloatware Creeps Into Android Phones". Wired. Retrieved 22 October 2014.
- "Want to protect your Android phone? Here's how to kill its crapware.". IT World. Retrieved 22 October 2014.
- "Friday Rant: The Ever-Sorrier State of Android Bloatware". Time. Retrieved 22 October 2014.
- "Samsung Galaxy S5 Bloatware Removal Guide". Laptop Magazine. Retrieved 22 October 2014.
- "Here’s how Verizon’s Android bloatware might become the best ever". BGR. Retrieved 22 October 2014.
- "South Korea rules pre-installed phone bloatware must be deletable". ZDNet. Retrieved 22 October 2014.