Make a business case...
Having fought this issue for quite some time I have a few insights to share. The first and perhaps most important issue to bear in mind is that your philosophy of what is "good practice" or not will generally have no impact on the people who control the purse strings. As with any major expenditure in a business, you have to make the business case for it. Thought it goes against the grain of most IT personnel, you will be best served to put together a formal presentation to your superiors, and include research, facts, figures, and preferably a demo. In our case, here is what our presentation consisted of:
We tracked the hours spend doing desktop support, and lumped the type of support into general categories. Those categories that could be made to "go away" with a desktop refresh/bit of modernisation were added together and the cost of the man hours spent on these categories was tallied.
We tracked the cost of replacement components, shipping as related to RMAing in-warrantee systems and other "hardware costs."
We performed an informal poll amongst staff asking what their biggest complaints about the IT systems were, and noted the % of these complaints that could be dealt with by new gear. (Morale is important too.)
We then gave a demonstration of the ease of maintaining newer systems (vpro demo, ghost deployments, etc.) and a quick lesson in how homogenous hardware deployments make IT’s life simple. (And a smaller number of spare units go a much longer distance.)
All told, this impressed the requirements of a desktop refresh on the paymasters, and it will be fitted into next year’s budget. The thing to remember is that everything has value...you simply have to find it. Hardware costs and the man hours spent on support are obvious ones. Don’t overlook the ease of udates (single set of hardware is single testing environment to worry about), image deployment, and disaster recovery (getting a spare unit out to the user.) Also always remember that especially in these "tough economic times" anything that boosts morale while also boosting shareholder value is a sure win. Presented in such a way…how can they refuse?