| Subject | English | Welsh |
| comp., MS | backup and restore | creu copi wrth gefn ac adfer (The process of maintaining backup files and putting them back onto the source medium if necessary) |
| comp., MS | backup file | ffeil wrth gefn (A duplicate of a program, a disk, or data, made either for archiving purposes or for safeguarding files) |
| comp., MS | backup withholding | dal wrth gefn (An IRS tax rule in the United States that requires notified payers to withhold a set percentage from payments made to payees who cannot be identified due to missing or incorrect taxpayer identification numbers on tax forms) |
| comp., MS | Complete PC Backup | Copi wrth Gefn Llawn o'r Cyfrifiadur (A tool in Windows Vista that backs up the entire computer (OS, settings, and files)) |
| comp., MS | Microsoft Outlook Personal Folders Backup | Copi wrth gefn o Ffolderi Personol Microsoft Outlook (In Microsoft Outlook, an add-in which creates backup copies of .PST files at regular intervals, enabling the user to keep Outlook folders safely backed up) |
| comp., MS | Personal Folders Backup | Copi wrth gefn o ffolderi personol (In Microsoft Outlook, an add-in which creates backup copies of .PST files at regular intervals, enabling the user to keep Outlook folders safely backed up) |
| comp., MS | tail-log backup | log gweddillion wrth gefn (A log backup taken from a possibly damaged database to capture the log that has not yet been backed up. A tail-log backup is taken after a failure in order to prevent work loss) |
| comp., MS | Windows Backup | Gwneud Copi wrth Gefn gyda Windows (A file backup feature of Windows Vista that performs scheduled incremental backups of data to the target media. It also allows the user to restore an individual file or a group of files) |
| comp., MS | Windows System Image Backup | Gwneud Copi wrth gefn o Ddelwedd System Windows (A tool in Windows Vista that backs up the system image) |