You've changed ram, removed batteries, and unplugged USB things. Laptops are simple things. That is you can make a list of the parts we can change on a very small piece of paper. The next part to change is the motherboard.
But first, did you tear it down to the motherboard then clean off the heatsink, CPU and put fresh heat sink compound and build it back up. Cleaning as you go of course.
My Toshiba laptop (Satellite M45-S331, OS is XP) locks up seconds after booting up. This started recently for no apparent reason. The only change in the laptop prior to its starting to lock up was use of a Sprint mobile data card. I am no longer using the card and have removed the associated software; however, it still locks up.
I set past restored points a couple times to no avail. I also installed a new hard drive and ran the systems? recovery disk but the laptop continues to lock up with the new hard drive. I removed the battery to start up only with the power cord and vice-versa (startup only with the battery), but it still locked up. I removed the 1GB memory chip and started up with the remaining memory chip of 512 ram and also removed the 512 ram and started it with the 1GB ram, but it still locked up. If it means anything, there are no ?restore points? shown in ?safe mode? (anybody know why?). Also, in safe mode, the system does not lock up nearly as often.
Is there some diagnostic test I could run on my laptop to identify the hardware issue causing the lockup, as it appears that software is not the problem (as the laptop locks up with either the old or the new hard drive)?