Well got a Dell Inspiron 5150 here, 3.06 GHz Mobile P4, 512 MB DDR RAM, Mobile Radeon 9000 with 64 MB VRAM, and here's the short story:
-Owner hands it to me, tell me it shuts down often.
-I at first think it's the battery.
-I realize later that the assumption is wrong.
-After updating to Windows XP SP3 from SP1, and realizing how bloated SP3 is compared to SP1, I find that the WiFi still doesn't like WPA networks.
-I then proceed to install Ubuntu 10.10, only to have the laptop overheat during the installation via Wubi.
-Laptop mysteriously overheats throughout the week.
So, recently, I took the whole thing apart, and took out the heatsink and dug out 1/2" of solid black dust out from behind it (not in it, behind it, lol), reassembled the thing, and voila Ubuntu installed without overheating again lol. Then the stupid WiFi driver didn't work in Ubuntu, and besides that it was kinda slow considering it had 512 MB RAM. So I uninstalled Ubuntu, and am now currently downloading the latest Windows WiFi driver off of the Dell website. Hopefully this will cure the laptop's WPA network problems.