PLEASE SEE THIS GUIDE WHICH I RECENTLY FOUND IF THE THINGS I WROTE BELOW ARE OF NO HELP TO YOU!:
This guide was written before I discovered the above link!.
Anyone with a SIS graphics card can get 1024x768 resolution without extra drivers, just follow the next few steps.
Go to > Applications > Accessories > Pluma text editor (or whatever your default editor is on your version of Ubuntu!) and paste the following text in the new file:
Identifier "Configured Video Device"
Now click on "File > Save as" and give it the following name:
Press Alt + F2 and enter:
gksudo nautilus in normal Ubuntu)
enter your password and find the file you just created (remember where you saved it?), right click and copy then follow this this path:
File System > usr > share > x11 > xorg.conf.d
Right click on the empty space inside the folder "xorg.conf.d" and paste the file!, close all windows and restart your PC, you should now have a res of 1024x768 without the need for other drivers.
Make sure your your "xorg.conf.d" file looks like the pic below before you restart! (Note the file "use-vesa.conf" is now bottom right of the folder!).
I tried this on Ubuntu Mate 14.04/15.10/16.04 and Lubuntu 15.10, Press any key at boot (Live CD or USB stick) then F6 and set boot option "nomodeset"; it works no problem although it might occasionally go into suspend mode during boot!.
Original info from here (thanks Greg!):
Here is a screenshot of Ubuntu Mate 15.10: