Problem booting up

Hello,
I have an acer aspire 7720-6381 labtop. I havw problems booting up my labtop. It goes as far as the microsoft emblem with the bars going across,thats where it gets stuck. I've called acer several times with no solution to my problem. Finally i sent it to their repair center in texas, when i receive it back i have no microsoft office and still have the same problem. I was told they did a recovery on my system, when i go in and look that what it says.However i still have a booting problem.
Most of the time for me to get it going i have to go to safe mode , msconfig, start up and uncheck everything , apply and then restart. Most of the time this works. Also i have to do this about 3 or 4 times a week. I have almost nothing stored on this computer. Oh when i first got this labtop a few months ago i did not have this problem. Ithink this started about two weeks after i got it and downloaded some microsoft updates, that were recomended.At the time i did not know that i should be more careful with downloads.
I took it to the geek squad at beat buys and they run a scan on it and said it was fine.Also i had them install trend micro internet security pro. They also disable or remove any other security system, so only one is running on my labtop.
OK hope someone can help me with this, THANKS!