1. The touchpad and external mouse drivers should be able to work together. Just make sure that you have the touchpad enabled. To see if you have the touchpad enabled, hold the Fn key and press F9. The combination Fn-F9 locks and unlocks the touchpad. If pressing Fn-F9 once, twice, thrice does not seem to lock/unlock your touchpad.. then you might not have the Toshiba hotkeys working or enabled. So lets forget it and try step 2. If Fn-F9 solved your problem.. there you go !
Arrow The way it works is you have to keep holding Fn key and have to hit F9 once, that should lock the touchpad. Again if you keep holding Fn and hit F9 again, that should unlock it and so on..
2. Sometimes this solves the problem.. Do a power cycle of your computer.. i.e., unplug the AC.. take the battery out.. Plug the AC back in and try to turn computer ON with AC alone (i.e, leave the battery out and just start computer with AC power).. Once windows loads up and everything is fine, then turn system off. Unplug AC.. put battery back in.. Plug AC back in and restart computer.. All should be working now.. if not, keep reading..
3. Click on START>go to RUN>type devmgmt.msc
4. Now in the Device Manager, click on the + sign next to Mice and other pointing devices. Right click on each device listed under "Mice and other pointing devices" and Uninstall ALL the MOUSE Devices you see listed there..
attention Make sure you ONLY uninstall the Mouse devices and not ALL devices from Device Manager like your CD, Display etc.. Just uninstall the devices listed under Mice and Other pointing devices after you have clicked on the + sign to the left of it..
5. Go to http://support.toshiba.com there click on Downloads.. select your computer.. Product=Portable, Family=Satellite, Model=M35X-S149.. then click on "GO" button on the right.. Again in the next page that comes up click on "Downloads"..
6. In the page that came up saying Downloads ( All operating systems, All categories ), at the top drop the list Filter by Operating System and select Windows XP (I am assuming you have XP.. if you have another OS, select that instead).. then on the right of it, drop the list Filter by Category and select Touchpad.. then click on the button "Apply Filters"..
7. Now you just see two drivers listed..
09-30-2004 Toshiba Utility
Touchpad Toshiba Touchpad Enable/Disable Utility for Windows XP (v22.214.171.124; 09-24-2004; 5.34M)
Touchpad Alps Touchpad Driver for Windows XP/2000 (v6.0.303.5; 05-26-2004; 2.43M)
Click on the Download link on the right.. Save them to your computer somewhere in a folder or desktop, where you can remember.. After the files are downloaded, double-click on the file.. Unzip.. then Run.. and it will install the driver..
8. Restart your computer.. Now the Touchpad should be working fine.. Try Fn-F9 combination.. i.e, keep holding Fn key and tap F9 once, twice to see if it locks/unlocks the touchpad..
If above doesnt solve it, then please post any errors that you get and I will see if we need to try something else.