Editing BIOS (section)

=== {{anchor|Flashing the BIOS}}Reprogramming ===
[[File:BIOS replacement kit.jpg|right|thumb|BIOS replacement kit for a Dell 310 from the late 1980s. Included are two chips, a plastic holder for the chips, and a [[IC extractor]].]]
In modern PCs the BIOS is stored in rewritable [[EEPROM]]<ref>{{cite book | url=https://books.google.com/books?id=V48MZCwICH8C&dq=bios+eeprom&pg=PA180 | title=CompTIA A+ Certification All-In-One Desk Reference for Dummies | isbn=978-0-471-74811-3 | last1=Clarke | first1=Glen E. | last2=Tetz | first2=Edward | date=30 January 2007 | publisher=John Wiley & Sons }}</ref> or [[NOR flash memory]],<ref>{{cite book | url=https://books.google.com/books?id=vaq11vKwo_kC&dq=bios+nor+flash&pg=PA2 | title=Inside NAND Flash Memories | isbn=978-90-481-9431-5 | last1=Micheloni | first1=Rino | last2=Crippa | first2=Luca | last3=Marelli | first3=Alessia | date=27 July 2010 | publisher=Springer }}</ref> allowing the contents to be replaced and modified. This rewriting of the contents is sometimes termed ''flashing.'' It can be done by a special program, usually provided by the system's manufacturer, or at [[power-on self-test|POST]], with a BIOS image in a hard drive or USB flash drive. A file containing such contents is sometimes termed "a BIOS image". A BIOS might be reflashed in order to upgrade to a newer version to fix bugs or provide improved performance or to support newer hardware. Some computers also support updating the BIOS via an update floppy disk or a special partition on the hard drive.<ref>{{cite book | url=https://books.google.com/books?id=E1p2FDL7P5QC&dq=bios+cmos&pg=PA393 | title=Upgrading and Repairing PCS | isbn=978-0-7897-2974-3 | last1=Mueller | first1=Scott | date=2004 | publisher=Que }}</ref>