Ask for updates, firmwares, drivers or a "fix" or replacement.
You've narrowed it down to the PC at least.
In closing, I've seen spyware do this too. Be sure you don't have any. Try EWIDO from download.com
I have a Dell Inpsiron with a Dell Wireless WLAN 1350 MiniPCI Card for wireless internet with Windows XP Home. My router is a US Robotics USR8054 router.
After my laptop has been running for an extended period of time, one of two things occur:
1) I can't connect to the internet. If I right-click the wireless icon in the system tray and choose ''repair'', it will repair the connection. After this, I open internet explorer and it won't connect, I open it again and it won't connect, but the third time I open it I have no troubles.
2) Even repairing the connection doesn't help, and it seems like my internet is dead. It works again only after I reboot my system.
My question is this, is there anything I can do so that my connection doesn't die at all? And why the heck in the first case do I have to open IE three times for it to work?