Can you give us a better picture of the setup please, eg;

1] How far from the router is this XP laptop?

2] Anything obstructing the signal, like cellar, walls, metal objects, etc?

3] Has this always happened with this laptop? If not, what has changed?

4] What other devices are attached (either wirelessly or wired), to the router? All the time, or just when the laptop loses connection?

5] Make and model router please, and what security is used, WAP, WPA, WPA/2?

6] If the router has a firewall, is this turned on?

7] What firewall does the laptop use?

Cool Have you tried a different channel in the router for the wireless connection?

9] Any scans done with your anti-virus scanner and anti-malware scanners? What utilities do you use?

10] When was the last time you rebooted the modem and the router?

Thanks

Mark