Little embarrassed here but ,, need help understanding what went wrong!

I have been using MSE  for a very long time , and also  IOBIT  , with no problems . But on Nov. 15th 2013 ,  I messed and in IOBIT  click on a drive booster , thinking it would improve overall performance and screwed up ,, cause now I have no sounds what so ever!   When I go to device manager to check , in volume , it says no audio device ,, and in sounds  there seems to be no sound scheme  assigned .  I tried up dating driver ; says using best device ,, and if you try to roll back ,  there is nothing to roll back to , as a previous driver . Now this is an older computer ,, Sony  VAIO   Windows XP , home edition , SP 3      Can a driver just disappear ??   And noticed when windows update ,, can not seem to update AND SHUTS mse off , then tells me " the feature I'm trying to use is a network resource that is unavailable "  never had that issue before either .  This all started that day ,, Did contact IOBIT ,, and they suggested downloading driver (s)  from Realtek  site ,,, I don't want to mess this up more than it is . Why I'm asking the community here for your knowledge on suggestions or advise .