Also, if you want any updates then you will need to download them
on a machine with Internet Connection and save of flash drive to
install on your desktop without the internet connection. Perhaps
updates are not important for you because you are not likely to go
online and not likely to exchange files.
I think many of the early updates were actual bug fixes, and you really
need to install them to get the best performance out of the OS. Now
that Win7 has been alive for a few years... not as much. Most of the
updates are security-related, which may or may not be very important if
you're not on the internet. In any case, you need AT LEAST Service Pack
1. I suppose some of the updates dated after that will enhance
performance and/or fix bugs, but Win7 + SP1 is quite a well-performing
setup.