How to keep your sensitive data secure

To do this in Windows XP, right-click the folder in question (My Documents, perhaps), select Properties from the pop-up menu, choose the Sharing tab and then click to place a tick in the ‘Make this folder private’ checkbox.

Vista users need not worry about this, as folders stored in standard user accounts are private by default (but they can still be accessed by administrators).

Administrator pitfalls
If the shared PC has more than one administrator account – one each for mum and dad, perhaps ­ then all privacy bets are off.

Any folders dad marked as private (an additional step in XP, as noted, but automatic in Vista) will indeed be inaccessible to standard or limited account owners, but because mum has an administrator account she will be able to rifle through dad’s folders whenever she wants.

How? Well, both Windows XP and Vista prevent even an administrator from directly accessing another administrator’s private files and folders. However, because an administrator has the power to manage any user account, all they need do is apply a new password to the account in question and they can log in.

So where a PC is shared by several people, do not consider user accounts a safe way of keeping files and folders private ­ unless the PC has just one administrator account and it is under your control.

Simpler security
So far we have concentrated on the privacy features attached to Windows user accounts. You may by now realise that, unless you are a sole administrator, they are not to be relied upon. So, what can the average user of a shared PC do to ensure their private files stay private?

Well, in the first instance it is worth exploring the options available in the software you are using. With Microsoft Office, for example, it is possible to add passwords to individual Word documents (or Excel spreadsheets, Powerpoint presentations and so on).

It is very simple to do and means that even standard or limited account owners can build some degree of privacy around their personal files.

To password protect a Word 2003 document, for instance, click the File menu and choose Save As. Now click Tools and from the dropdown menu pick Security Options. Here it is possible to set passwords both for opening the document (most secure) or modifying a document (which does not stop anyone from opening the document but will prevent changes being made).

Also, if you are really concerned about privacy, click the Advanced button here and choose a strong encryption type. Word 2007 users should click the Microsoft Office button, choose Prepare and then click Encrypt Document.

This method can be applied in much the same way across all the Microsoft Office applications. However, it is worth bearing in mind that this protects only a document’s contents from being viewed: a computer administrator could still view the file name. So, if you are craftily updating a CV on a work PC, remember that saving the document as ‘Bob’s updated CV.doc’ might just give the game away to anyone who comes looking.