Reason of not updating computer- Endless Cycle

From the reading “The policy Implications of Internet Connectivity in Public Libraries” by P.T. Jaeger et al, it mentions that 13% of public libraries reported budget decreases, and 96.4% of public libraries have no set upgrade schedule internet access.
And then authors wrote some reasons of limiting upgrading: endless upgrade cycle, technological support and maintenance cost, and building & space limitations.

I thought the “endless upgrade cycle” is interesting and wroth for some discussion. Microsoft upgrades its operation system every 2~3 years and there are LOTs of new programs and software coming up. If I were a manager of a library, I wouldn’t know what to upgrade, because even if I upgrade computer now I will have to do it again very soon.
Right now in the libraries in the University they have pretty up-to-date programs like FireFox and Word2007, however, some local libraries might be still using Windows and word2003. I think it is just hard to judge if the libraries should spend the money now or wait for 1 more year when the newest programs come out.