There is hardly ever one overwhelming reason which compels such an investment or move - just as there is no single compelling reason for maintaining and refurbishing other infrastructure systems necessary for the conduct of business, or even for refurbishing offices themselves. There are, rather, a whole range of reasons why no business should let its IT systems get outdated. Obtaining continuing support is a problem with old systems. For example, users running WordPerfect 5.1 will find it increasingly hard to buy a new printer that is compatible. Also, all the development and bug-fixing effort goes into current software, not obsolete versions.
Old software has less functionality, so productivity is lower.
Obsolete systems make staff feel that they are in the career doldrums and their job satisfaction and morale suffer. This has been shown to have a direct relationship to staff turnover and the ability to attract new staff. If you buy the fastest PC available, you should expect to replace it in three years, if not sooner. IT expenditure should be seen as a continuous expense, not an infrequent capital spend. In order to gain access to the free legal information sources on the Internet, a firm has to provide Internet access within the office.