I hate slowness on computers - here's what I found to help, some of which I am still working on:
- run the amazing utilities optimizer weekly
- put in cheap gigabit NICs in the client computers
- make sure you have a gigabit switch
- don't bother putting in extra NICs on the main computer or server, mostly it can't use them, especially if the clients don't have two NICs. Make sure it does have a gigabit NIC.
- if using a server, run a MS Best Practices Analyzer - it will find out if your system is using TCP offloading algorithms that will slow down a network that is not using SAN disks and fibre channel
- buy a nice managed switch
- maximize your servers disk access speed with 5-disk RAID 5, or SSD drives
- finally, go virtual with thin clients
- check if some computer is doing heavy internet access at the slow times, as I found that sometimes really slows everyone down. Run SpeedCheck when you're slow - I'm not sure how slow internet access slows down the whole network, but it does.
