I'm getting tired of syncing my address book over and over again with different devices; I had to do it when I switched from a BlackBerry to an iPhone and from a Windows PC to a Mac. Is there software available that can do it for me? Name and address supplied DQ: The problem is all about standards. Many in the computer software industry support open standards, others do not. You ought to be able to move your data from one application to another. The reason this remains difficult is the different ways software handles data. The first thing to do is to keep all your contact data in a separate database, possibly in vCard - a file format standard for electronic business cards. Address Book on the Mac OS X operating system allows you to export all of your contacts in one vcf file, while Microsoft Outlook only accepts one contact per file. If you need to get conversion software for Windows, try www.processtext.com/abcvcard.html . You should print out your database; twice, in fact. Print it once in high resolution 14-point typeface and keep it safe. Print another smaller typeface version with only telephone numbers and e-mail addresses. Take this with you when travelling. You will be able to find the contact details whatever happens. I keep getting messages in my inbox with the attachment 'winmail.dat' from different sources in different sizes. What should I do with it? Tom, Sheung Wan DQ: You are obviously a Mac user, because the winmail.dat file was a previous attempt by Microsoft to make it easier to send attached files. Unfortunately, as so often happens with Microsoft, it forgot that about 10 per cent of the world's personal computers did not use the Windows operating system and the Office suite. Winmail.dat could have been a good idea, if the world used nothing but Microsoft software - which would, of course, be a decided-ly bad thing. In earlier versions of Outlook, Microsoft would handle the sending and receiving of attachments and these would appear on your desktop. The flaw was that it only worked if Outlook and Windows were at both ends of such correspondence. There are two ways to fix this: ask the senders to fix the problem at their end. However, that could be difficult or inappropriate if your e-mails are from a customer. You can also download a simple application to extract the original file for you. TNEF's Enough converts winmail.dat files for a Mac user with a simple click of the mouse. Visit www.joshjacob.com/macdev/tnef for more details.