Upgrade
I need a CD writer. Rather than spend cash upgrading my five-year-old Windows 98 PC, it would seem more sensible to buy a new machine using Windows XP Home. Should I be able to transfer and access existing files and programs? It is vital that I retain my email address: should this be an easy task to set up again on the new system? I was thinking of a Compaq package which I note uses either Intel or AMD Athlon processors. Is this a major factor in one's choice? Most of my work is emails, simple spreadsheets and word processing. I have just got a digital camera: hence the need for a CD-RW to back up pictures to disc. Gavin Elliot

Jack Schofield replies: Windows XP has a utility to collect and transfer important information from your old machine, so it should not be hard to get up and running. There are also programs that will transfer things from one PC to another via a serial cable or other connection: one example is Aloha Bob's PC Relocator. However, I prefer to install software from scratch: it means you get a clean start, and can avoid mistakes you may have made earlier. The drawback is that you need to have kept original software CDs and registration keys (which are probably on the packaging), and copies of any programs you downloaded that may no longer be available. Also, it may take a day or two to get everything back to a state that makes you feel comfortable.

Once you have customised the new system to your satisfaction, it is a good idea to take a backup of the hard drive using Centred Software's Second Copy, Norton Ghost, Drive Image or a similar program. Manufacturers often provide a CD to return a PC hard drive to its factory condition, but if you have to resort to that, you will have to re-install all your software and customisations. Also, if you did not keep original CDs handy - I use a yellow plastic briefcase to store them all together - and a notebook to log things like IDs and passwords, then this would be a good time to start.

For your purposes, it really doesn't matter whether you use an Intel Pentium or Celeron processor or AMD chip. A 1.3GHz or slower chip will handle these tasks comfortably, but even cheap PCs usually run at twice that speed today. If you are working to a budget, it is better to spend the money on more memory - get at least 256MB and preferably 512MB - and on Windows XP Pro rather than the home version.

Too much
I have a 40GB hard drive with 38GB of free space. When I try to copy a 4.3GB file, Windows says I don't have enough space. Is there a limit to the file size on a Fat32 drive? Mike Campbell

JS: According to Microsoft's Technet, the maximum file size in the Fat32 disk format is 4GB minus 1 byte. This was one reason Microsoft switched from FAT (file allocation table) to NTFS (New Technology File System) when Windows NT was launched in 1993, and this should be the standard file format for Windows XP. I would try this but my PC doesn't have a DVD drive or the free hard disk space.

Backchat

· Brian Lapworth and Jerry Hathorn asked about scanning negatives and slides, and Jerry complained that using a flatbed scanner, images came out black. David Harper had the same problem and says: "Epson's user manual isn't all that helpful on the subject of film scanning, so it was only after some investigation that I discovered you need to remove the white reflective plate that clips inside the lid before you scan film. After that the results were exceptional."

David says he uses a Nikon CoolScan IV to scan 35mm slides: "It's a fantastic bit of kit, and fierce competition has seen its price nearly halve recently to £399." He bought an Epson Photo Perfection 3200 flatbed to scan medium-format (6x6cm) slides. He says: "I'd thoroughly recommend the 3200 to anyone looking for an affordable way to digitise larger film formats to a very high standard." Martin Harradine also bought one and agrees it produces very good results. However, he adds: "From February 1, Epson is bringing out the 4870, which looks like rewriting the books on flatbed scanners altogether, making dedicated film scanners virtually redundant." Martin recommends www.photo-i.co.uk as a source of information.

· Ron Ross and other readers also wrote in with advice. Ron suggests reading reviews in camera magazines rather than computer magazines as "the latter often spend too much time thinking of the technology, and not enough of the final products". He also suggests buying a "previous-generation slide and/or film scanner" which are often sold off at a quarter of the price.

Ian West and Alan Simpson both recommend the Pacific Image Primefilm 1800 (about £130) as a cheap option. Ian says: "The results are good enough for most purposes." Alan Murray-Rust suggests buying a scanner that has an external graphics package such as Photoshop Elements. "Don't use the inbuilt software that allows corrections to be made at the time of the scan: if you get the corrections wrong you will waste time rescanning the slide. With an external package, it is much easier to get your adjustments right."