After almost a decade of service, the end-of-days is drawing near for the long-lived and very widely used Windows XP. It has entered legacy mode with the end of mainstream support.

The extended life of Windows XP was partly due to economic conditions hampering spend on desktop upgrades and partly down to Windows Vista failing to get off the ground successfully in the business sector; it never really recovered the confidence that was lost in the early days because of compatibility, performance and usability issues.

Nevertheless, we are were we are, with many organisations relying on a desktop operating system designed over a decade ago that is facing obsolescence, with all of the direct and third party software support and maintenance implications that come with that. It is a position that is not sustainable for much longer, unless you are willing to live with escalating cost and risk.

Every day extra spent running Windows XP adds additional risk to the business as support costs increase, security issues escalate and software vendors target their products and support at newer Windows releases.

With this in mind, while other options exist, the most obvious way forward that most organisations are considering is a move to Windows 7. This has been pretty well received and represents a massive turnaround. It is Microsoft's fastest selling operating system and has become widely adopted by consumers and also small businesses in the year since its release. Now we are seeing signs that mid and large sized companies are preparing to make the move too.

Windows 7 is a derivative of Windows Vista, albeit a much improved one, so benefits from a lot of the ground work done in terms of compatibility, interoperability, security and manageability. While it has only been around for a year, much of the components and core features have been road-tested and optimised for significantly longer than that.

So is it just a case of out with the old and in with the new? Well clearly not. Despite the general level of comfort with Windows 7, there are many practicalities to still consider.

Doing a straight switch from Windows XP onto Windows 7 may seem like a simple approach, but migration in practice takes extensive planning, testing and remedial work, which is costly and time consuming. This work needs to be performed on legacy applications as well as new ones, as well as looking at the underlying hardware.

Beyond this familiar territory, if you think a little bit ahead and consider also other changes that are happening to the PC, it may help to alleviate or avoid issues that if retrofitted at a later date could increase risk and costs and decrease the capabilities of the solution.

On the software front, the Windows 7 migration is a good opportunity to evaluate, test and introduce up-to-date versions of software. This is true for specialised software as well as more general productivity suites, and particularly Office.

Many of the companies that we have surveyed are still running Office 2003. Although it is still reasonably functional, it is showing its age with a lack of support for new document features and standards, less capability to support mobility and a higher incidence of security issues.

Like Windows Vista, many companies avoided the big change that was Office 2007. Office 2010 continues the evolution of Office, and enhances much of the interaction with back office functions such as Exchange, SQL Server and SharePoint.

After the upgrade licence costs, testing and user training are some of the biggest expenses involved in upgrading Office. As extensive training and testing have to be done as part of the Windows 7 migration, it makes sense to take advantage of the activity to support an Office switch.

Looking at the underlying hardware, there are a couple of big changes to consider. The first is whether to move to 64-bit support or not. Windows 7 has a 64-bit version that can perform much better with increasing memory capacities. The beauty of it is that, from an end-user perspective, it is almost indistinguishable from the 32-bit flavour.

So the issue here is whether it is best to jump straight to 64-bit at the same time as adopting Windows 7, or to wait and only migrate when applications demand it.

The advice here is to leave your options open. As applications and hardware may behave differently, it is definitely worth testing them on both 32-bit and 64-bit for compatibility. This will identify any issues that may cause problems when moving, and allow workarounds to be considered – for example using the built in Windows XP mode of the business versions of Windows 7.

Ultimately, most applications are likely to lag the operating system by a number of years in moving to 64-bit. This may seem like a compelling reason to stick with 32-bit for the time being. However, without moving the platform to 64-bit there will be no opportunity to run applications that have been updated to take advantage of the extensions without a time consuming and costly re-installation of the operating system.

Beyond performance and compatibility, the ever-increasing move to mobile working and the more sinister nature of threats and malware means security is high on the agenda.

An upgrade presents the opportunity to introduce additional security in the shape of encryption for data and information. The encryption functionality can add significant overhead, so the introduction needs to be carefully managed.

It may need hardware upgrades, particularly modern CPUs with encryption acceleration or Solid State Disks (SSDs), to maintain performance.

Whatever your migration plans for Windows 7, it is important to look at the wider view to take advantage of the biggest transition in years to improve and optimise the capabilities of the PC pool as retrofitting at a later date may be expensive and time consuming to implement.