
The analyst firm urges organisations to start these testing processes immediately. A new briefing written by analysts Michael A. Silver, Stephen Kleynhans and David Mitchell Smith estimates that testing will take at least a year for most firms.
"For most organisations, we believe 12 to 18 months of testing, planning and piloting will be required before mainstream Vista and Office 2007 deployment begins," the briefing stated.
"Organisations need to understand their software inventory, do internal testing and work with independent software vendors to understand their support policies and timelines. If you haven't started this process yet, consider starting now.
"The sooner you want to begin deploying Windows Vista and Office 2007, the sooner you need to begin testing.
"Organisations that run Windows 2000 and are trying to skip Windows XP should have already begun. Organisations that want to deploy in early 2008 need to start shortly."
Gartner noted that Microsoft "surprised" many of the companies creating add-ons to for Windows Vista by meeting its goal of releasing Windows Vista to manufacturing in 2006.
"Because of this, much of the ecosystem in terms of drivers and applications is not yet ready to support Vista," said the analysts.
"Furthermore, Microsoft has got very good at deploying fixes through Microsoft Update. Gartner expects significant fixes and additional drivers to be available before the consumer launch at the end of January 2007 and to continue to come through Microsoft Update."
In light of this, Gartner warns enterprises to expect "continued change" as Vista matures.
It goes on to point out that Microsoft Update will mean that service packs are less critical, since the more important fixes do not have to wait for a service pack to be released.
According to the analyst firm's briefing, the amount of work necessary for successful and smooth Office migrations should not be underestimated.
"A new user interface and new document format mean that organisations will need to plan training and policies, and understand how various versions of Office, whether they are used internally or by business partners and customers, will interact," said the analysts.
Organisations that have not started to prepare for Vista should begin by taking inventory and working with independent software vendor partners to understand the implications of Vista and Office 2007 implementation.
They should also monitor Microsoft Update and expect changes as the products mature.
According to Gartner, firms should consider developing an internal IT communication plan to address possible internal end user inquiries about migrations.
Software Assurance customers should look at their contracts to understand whether they have rights to these new products, and understand what training vouchers and Desktop Deployment Planning Services they are eligible to use.