Hello, I have a toshiba satellite a75 was running windows XP and now 7. When I upgrated to windows 7, the fans started to turn on even though the laptop was cool. Also, the charging doesn't work while on. I calibrated the battey and didn't work. I upgraded windows 7 by disk.
The issues are highly unlikely to be because of the OS upgrade. Just a timing coincidence.
In regard to the fan, I would still use something like "Speedfan" or other monitoring program to check the temps and speeds for fans to see what is going on. It could be overheating (even though not noticing it outside the device, or it could just be the fans time. They do go after a while. If the temps are fine, I would consider replacing the fan.
As to the battery. If it is charging fine while the laptop is off, but not when it is turned on, then you probably need a new charger cord.
When they are damaged (and you may not see the damage) that causes them to not put out enough power to both run the device and charge the battery at the same time, but will charge the battery fine when not powering the device. Eventually it won't do that either.