Sound problem makes me crazy...

Hello everybody, first of all my apologizes for my approximative English, i haven't studied it for long and i don't use any translator. So why i post here ? Simple i searched since last week first on French forums and now here because i have no more options to solve my problem, i'm about to reinstall xp, this is the last chance i accord to this windows 7 ultimate "issue".

My laptop is a lenovo y510 with a sound chipset using the "realtek high definition audio drivers", on xp sp3 the quality was perfect, on w7 it's a mess. First there is a delay, for example i open a folder, i test the audio on the task bar, etc the sound takes approximatively +0.5 second to active himself, except when i play a continuous sound (music/video) here the sound appears in the normal delay, very strange...

Second problem, static, crackling, i can't listen music or any kind of sounds while i'm working (maximize a window, scroll a word/excel document, etc...).

Third problem, the worst, my onboard speakers (5.1) ALWAYS create crackling at the begging and at the end of any sounds, even when i plug the external speakers, and if i up the volume of my external at nearly maximum i can here the sound from my onboard too (weak but present) !

I tried everything people advised me, all drivers from 1.84 to 2.47 (include different compatibility) and windows updates ones, disable power management, powermizer, tried everything on the control panel in sounds settings, flash the bios, update motherboard chipset, low level format + proper install... NOTHING works, i start thinking there is nothing to do except pray for a decent driver release, i can't believe it's an hardware problem everything worked good on xp ...

Thanks if you can advise me, i'll follow this tread with great attention !

Regards.

EDIT : -Same problem on vista
- With the basic driver just after the installation of W7 it's ok, but all the speakers are split impossible to "combine" or make them work together (plus i lose all the useful options of the realtek center).

This explains Larry Osterman's WebLog : What is AUDIODG.EXE?