Software products for automating back-up can help overcome the difficulty of persuading end-users to copy their work to back-up media and keep it somewhere safe.
The choice of methods and media used to back up desktop PCs has expanded in recent years.
The traditional dominance of magnetic tape is being challenged by everything from CDs and memory sticks to central back-up managed across a network.
Services companies are offering to take the whole business off users' hands - as long as they are happy sending their data for back-up via the internet.
Software products for automating back-up have emerged to beat a long-standing difficulty inherent in traditional approaches: persuading end-users to copy their work to back-up media and keep it somewhere separate and safe.
Robin Burke, global research vice-president at analyst firm Gartner, said users rarely spend much time or effort on a comprehensive desktop back-up strategy.
"It is a low-key area - and I suspect a lot is ad hoc and not organised by IT professionals," he said.
Major software and hardware suppliers - including Microsoft, Cisco, Computer Associates, Symantec and EMCÊ- are trying to get IT to take control, with products that automate back-up for end-users or enable management from a datacentre, or both.
Computer Associates principal consultant Nigel Tozer said, "Unless someone has suffered data loss it is unlikely they will use any hardware provided, and even if they do, complacency will always creep back in."
Tozer recommended that money spent on back-up equipment, such as CD and DVD writers, or USB devices for individuals, is far better invested in an automatic system that requires no action from end-users to keep them protected.
Back-up from disc to disc is taking hold here; typically only data that has changed is backed up and only one copy of duplicated data, such as e-mails sent to several people, is held. This is sometimes referred to as single-instance storage.
Even so, Microsoft encourages users of its System Centre Data Protection Manager - a server application that optimises disc-based back-up and recovery - to back up again to tape and store the tape at another site in case of a natural disaster.
In addition data backed up to disc can periodically be sent across a network to a datacentre. An extension of this approach is wide area file services (Wafs), which are being promoted by Cisco and others.
Wafs take all data away from a remote desktop installation, such as a branch office, and keep it centrally maintained at a datacentre, where IT specialists include it in their professionally managed back-up procedures.
One area to watch out for is the type of protocol used by the application.
Ian Bond, systems architect at Cisco, said, "Running file services over even a very high speed wide area network has not really been feasible before because systems such as Word are very chatty and assume you are working over a local area network.
"It takes about 700 serial transactions just to open a Word file. That is OK over a Lan but it means poor performance over a Wan, where speeds are far slower."
The Wafs system has been developed to overcome this performance hit. It is designed to help IT directors achieve the goal of consolidating servers and storage. It can also be used to get IT under central control of specialists, Bond said, adding that back-up management was not the first aim but it has emerged as a significant benefit.
"With Wafs we put technology in the remote office and in the datacentre. It can be an appliance with no disc or software to maintain, or it might be a module to plug into a branch router.
"It manages the communication but stops 80% of the chatter, while maintaining the integrity of the conversation and the data. There is no change to the application and the service is transparent to the users."
Wafs cost a few thousand pounds of initial capital spending per office, but Bond said that is usually paid back in well under a year, especially if the full potential beyond just back-up is exploited.
Research firm Yankee Group estimated that without Wafs the capital spending of a branch office with a mid-range file server and other servers would be about £30,000.
As part of this, a back-up device and software might cost well over £4,000, and then there was the cost of staff time for backing up, if the people remembered and were disciplined enough to do it properly.
The idea of leaving back-up to IT specialists is also a selling point for internet services, especially if connection and transmission are set up to be automatic, at set times for office staff or when a mobile worker links to the internet.
Burke said online services benefit organisations with mobile staff, and again underlined the need for an automated process. "If it is not automated, forget it: it will not be used," he said.
A laptop being used in a hotel room, like a PC on a desk, holds some of an organisation's most valuable information, because it is the very latest.
Thinking Safe is a new company offering a service to tackle remote back-up for mobile workers. The company is unusual in that it also offers its software for sale so that organisations can run the service themselves from their own datacentres.
Ed Jones, a back-up and disaster recovery specialist, said, "A file that is out and about on a laptop is most at risk in its first week of life, because people tend not to save information onto the network until they are ready to share it.
"Recently systems run by service providers or implemented as software have given the ability to manage the back-up of the very latest 1% or 2% of a company's data, even if it is on a laptop in a hotel room."
Thinking Safe users include international IT services group LogicaCMG and GB Airways, which has 1,250 staff across 35 offices accessing 400Gbytes of data.
Online services take their own medicine. Thinking Safe, for example, offers users a back-up device in their own offices, with mirrored discs, plus mirrored discs on its own system, plus a link from there across the internet to another site.
Online service costs vary considerably, from less than £10 a month for 1Gbyte and to anything from £40 to more than £700 a month for 100Gbytes, depending on factors such as the level of automation, the provision of 24-hour helplines, bandwidth charges, data compression, encryption and guarantees.
Online services and Wafs are relatively new, and if end-users are left to their own devices on back-up they still tend to stick to traditional approaches, at least for now, according to removable disc and tape manufacturers, which continue to enjoy boom times. Sony is finding 10% annual growth in demand for its tape systems in the mid-range market, for example.
"We are coming across Wafs in big corporations but it takes people time to adapt to something new, and they often prefer local distributed back-up in any case," said Will Trotman, product manager for Sony's Advanced Intelligent Tape.
He said tape development was continuing, and life length and reliability were still increasing. Tests of Sony's latest tapes showed a life of up to 30 years, although 10 to 20 years was more realistic, and less than that if a lot of rewriting was being done.
A 20Gbyte Sony tape costs £15, and a drive is £280. This compares with £35 for a 35Gbyte removable disc from Iomega, for example, and £229 for a disc drive.
"The trend is towards the removable disc, and prices will fall but at present for long-term archiving - for example, of e-mails - tape has advantages, not least the fact that it is cheaper," said Burke.
"The growth of data and regulation compliance issues that demand we keep more and more of it mean we cannot continue to throw disc arrays at it: we have to archive it off."
Spare capacity on PCs could be used for back-up, with the right software, said Jones. "Desktop machines typically have an 80Gbyte drive, and if you have 400 of them that is a lot of space, and probably most of it is not being used. You have the capability here to build a back-up and recovery environment without buying extra hardware."
At the other end of the market Burke saw DVDs emerging as back-up, especially for home PC users and possibly in business. DVDs are cheaper than discs but capacity is less than 5Gbytes, although double-sided DVDs are appearing.
Burke found memory sticks useful for personal back-up when travelling: the memory device can be kept separate from the laptop, and if the machine is lost or stolen the data is still available. But such devices are not realistic for long-term archiving.
There are debates about the relative durability of tape and disc, about management issues, such as the need to load and unload and label the media, and about disc random access compared with the serial recording and access of tape.
The latter can become an issue if tape is used in back-up systems that only write changes to the back-up media rather than complete files, because if a file has to be restored its components could be in different places.
But how often is a back-up system called on? Statistics are hard to come by. Jones had one customer with 400 users at one site doing 10-15 restores a week, mainly of single files.
Theft is another area of concern. Derek Lloyd, managing director of PC World Business, which runs an online service, said, "Research shows that more than 2,000 laptops are stolen or lost in the UK every day, and a hard drive crashes somewhere every 15 seconds. One in five of all computers will suffer a fatal hard drive crash during their lifetime.
"It is estimated that 43% of companies that suffer large-scale data loss never reopen, and another 29% close within two years. The risks are enormous, and businesses need to take data back-up seriously."
People often delete something, either intentionally or accidentally, and then want it back. Or users just cannot find a file and go for a restore.
Whether it is to protect against data theft, a disc crash or accidental deletion of a document, backing up desktop and mobile PCs is essential.
Fortunately, online back-up services, and developments in back-up media and software makes the process of backing up company data on these devices a lot easier.