How to improve Dealing room support?

HI,
I am working as Dealing room IT coordinator in a big bank in my country, I would like to know how to improve the services provided to the 50 users (dealers) which I support (business and technical wise). The applications used are as follows:
-OS WinNT 4.0 with SP4
– Reuters terminals software
– Bloomberg terminal software
– Office 97
– Outlook as email

The hardware details are:
– Compaq Deskpro EN series 350MHz
– 128MB memory
– Dual VGA cards (which supports up to 4 monitors)
– 6GB HDD

Could some one advice me please how to improve the security, backup system, disaster recovery etc..

Thanks