MS-DOS 5.0 was a major upgrade. It allowed parts of DOS to load itself in the high memory area and certain device drivers and TSRs to run in the unused parts of the upper memory area between 640K and 1024K. This version also added support for IBM's new 2.88 MB floppy disks. An improved BASIC interpreter and text editor were included, as was a disk cache, an undelete utility and a hard-disk partition-table backup program. After the problems with MS-DOS 4, it also provided a utility to make programs think they were running on a different version of MS- DOS. Couple of minor bugs with Undelete and Chkdsk utilities were fixed in version 5.0a.
Microsoft DOS 5.0 was the first version of DOS that offered an upgrade version which was designed to be installed over the top of a previous version. This feature was touted in a unique promotional rap music video featuring the refrain 'Gimmie Five'