Perhaps a more serious reply ...
On failure, you might be able to check the router to see if the laptop has an IP address leased. No connection + leased address = your laptop lost it's IP mind. First bet is a software problem. Reinstall drivers. If that doesn't work, blame the hardware.
If there is no IP address on the router leased to the laptop, check the laptop to see if it's got an IP address (cmd: ipconfig). In this case, I'd bet against the router.
In any case, rebooting the router or the laptop causes all new leases to be acquired (not to mention a fresh software driver load).
If you have another "stable, known good" machine (i.e. not a Compaq or HP), and it never loses it's connection, it's the laptop.
Good luck,
rr
