I'm not familiar with this 10.18.10.3643 driver version, however; you will be able to find the latest driver for your graphics controller at Drivers & Software and if you want give it try with Intel® HD Graphics 4000 drivers here you will find latest drivers Drivers & Software.
Thank you for your answer. Updating to the latest driver has worked and the graphical glitches in KOTOR are gone! (For me, the latest version is 10.18.14.4332, for Windows 8.1 x64 and HD Graphics 4600.)
In case this helps anyone else, here is what I tried before I managed to make it work:
- Tried to use the Device Manager to "Update driver". For some reason instead of using the latest Intel driver, it was reverting me to an old version of the driver (10.18.10.3643), which appears to date from 2014.
- Downloaded the ZIP file of the latest driver from the Intel website and extracted it, then tried navigating to it via the "Update driver" command in the Device Manager, but it insisted I had the latest driver and didn't update.
- Tried running the Setup.exe file from the extracted ZIP, but received a message saying something like “Driver not validated for your computer” and the update didn't work.
- Tried visiting the Acer website to get what Acer thought was the correct driver (my laptop is an Acer Aspire VN7-791G). Acer still lists the old driver (10.18.10.3643) as the latest one. (Maybe this explains why my computer was convinced I already had the latest driver? No idea.)
- Found this thread from Kevin at Intel (Graphics Driver installation problems), which recommended uninstalling old drivers before trying to install new ones. Used the device manager to uninstall the current (old) driver. This left me with driver version 10.18.14.4264 (the one my computer had "rolled back" to before, despite the fact that it is more recent!)
- Tried uninstalling the driver again, but for some reason when I restarted the version still said 10.18.14.4264. Decided I had done enough uninstalling.
- Downloaded the EXE file of the latest driver from the Intel website. Executed that, and it ran and restarted, and the install worked fine. I started the game and the glitches are gone!
TL;DR what might help is:
- Uninstalling the current driver before trying to install new one.
- Using the EXE file for the new driver instead of the ZIP. (It doesn't make much sense but it worked for me...)
- Don't believe the Acer website or the Device Manager about what driver version is the latest one.