Question on system restore

I'm having some very strange problems with not getting any audio on youtube videos. I have a pretty detailed post here of everything I have tried with so far to no avail. Strange audio problem occuring . Basically I get audio when watching videos on Vimeo and other non YT sites that hosts videos. I am able to get audio on YT ONLY if I use google chrome. I get no audio when using firefox or IE

But one of the options I was advised to do regards doing a system restore. I made some motherboard (with onboard sound) updates which could be part of my problem ( see link above for full description of what happened there) I did create a sys. restore checkpoint prior to doing the motherboard updates. but here are my questions on the system restore.

- I have attempted the system restore twice... once in regular mode, once in safe mode. after choosing the checkpoint.. the first screen that appears is something that says "please wait.... system restore is initializing" But it will not get past this screen... I have waited over a half hour and nothing changes. Finally I bailed out with a hard shut down.

What is the typical time period this first initializing screen stays up for? I do have a lot of TB's of data and a lot of programs.

-I may have to go even farther back with checkpoints... but if it doesn't work again.. this would be even further concerning to me.

-If anyone can take the time to read the link above on the audio problems with YT that prompted this whole mess and has any thoughts or ideas I sure would welcome any help.

Well I was able to get system restore finally to go thru.... I found an old post here where someone recommended while in safe mode to access the system repair option thru the "advance boot options---repair your computer--system recovery"
so this time it did do the restore.