Windows won't start after updates

Question - We live in Spain for a few months of each year and rely on a dial-up internet connection while we're there, as broadband is very expensive. This is fine for email and so forth, but for obvious reasons our laptop, which runs windows XP with service pack 3 (sp3), is not set to receive updates automatically. Once a year we visit friends who have broadband and take our pc so that we can download the latest updates (both to windows and avg, our anti-virus program). Previously this has been fine, but this time when the pc restarted, windows would not launch properly: it gets so far before restarting. it seems the updates didn't go well, but I can't now get to the point where I can launch system restore in order to go back to the point before the problem arose. Can you help?

Answer - probably the best bet is to try starting your PC in windows safe mode and then launching system restore from there. To do this, tap f8 repeatedly soon after switching on your pc. When the boot menu appears, use the cursor (arrow) keys to highlight safe mode, then press enter. Log in if requested and then your familiar windows desktop should appear, albeit looking bereft of color and resolution -this is normal for safe mode. Now click start, then point to all programs followed by accessories then system tools and click system restore. Now follow the system restore wizard to attempt to restore your pc to a time before the updates were applied.

Assuming this works, at the next opportunity to update we would suggest working methodically, manually installing a few at a time - this will help to isolate the cause.