Welcome to cdfreaks
The great thing about Liteon drives is that they can always be restored.
1/ Never use mtkwinflash on Liteon DVD writers. This program is for CD-RW drives.
2/ Your drive will always be an 812S, so you always have to use crossflash patched firmware for it to work as an 832S.
3/ Always use the crossflash patched (-cf) 832S firmware on my site or us OmniPatcher to enable the crossflash patch on the unscrambled 832S firmware on my site.
Ok, now for the fix. Since your drive is not detected by windows you will need to use MTKFlash. This is the procedure I recommend:
1/ create a bootable dos disk. Remove all files except command.com, io.sys and msdos.sys (the system ones)
2/ download mtkflash 1.80 from http://dhc014.rpc1.org/howto.htm
3/ Add MTKFlash.exe to the disk.
4/ Get US0Q.BIN from http://dhc014.rpc1.org/Files/DVDR/SOHW-812S_US0Qb.zip.
5/ Add this to the disk.
6/ Select the jumpers on your drive for master and remove all other drives.
7/ Boot to the floppy.
8/ Type in MTKFlash 3 w /b /m US0Q.BIN. The 3 is secondary master. See the step 2 site for details.