Following Paul's review I decided a clean install would be the way to go. Unfortunately the sounds seem to get corrupted when I apply this update. Any ideas why this may happen.
Never heard about this kind of issue...so tell me more :
What is your windows version ?
What are your PC specs ?
What did you do exactly ?
Install from dvd or steam ?
Perhaps the game is lagging and sound stuttering because of low pc specs or on contrary your processor is fast but doesn't use multi cores ? In this case I suggest to enable multi cores with softwares such as bill's process manager or bitsum process manager and enable at least 2 cores for GTR2.
Did you check archive md5 checksum once downloaded ?
Perhaps archive is corrupted so retry download.
Do you have latest 7zip archiver version ?
Archive was compressed with 7zip v18.05 so this is the minimal version you should have installed.
I suggest you to delete all and restart :
1) new clean GTR2 install either from dvd (is your disc scratched???, maybe clean it) or steam
2) download again 10th Annivesary Patch and check md5 checksum with the one provided on overview page at RD
3) extract archive with 7zip (18.05 minimum) where you have installed GTR2 : you must click YES to overwrite ALL files and folders
4) you MUST go inside GTR2 directory and right click on every EXE file in order to set WindowsXP compatibility + Administrator rights, otherwise you will get many issues under win7/8/10
5) run gtr2config.exe and set your screen resolution in 32bits, choose directX9 and nothing else (set AA/AF in your graphic card driver instead)
6) run GTR2.EXE
If it still has same sound issue then I do not understand why because my patch doesn't modify stock WAV sound files (only one in m3gtr is replaced to fix stereo)