Sound problem

[MaximusCat]

Model VPCEJ3T1E - I ran a Vaio software update this morning which included the sound software. After installation the system sound was disabled. I have managed to reset this but the volume level is poor. Before the update I used a 25% level; following the update I now need to use 80% on the slider to hear anything. Can someone explain why this has arisen and if appropriate how to correct it or uninstall the update.

I am not particularly computer literate so please no jargon:)

Thanks