My acer aspire is taking too long to boot up..once its on,it works fine but the sounds are different,the start up sound...and when i play videos,they work fine but the sound lags and distorts

Maybe because there are so too many start up programs try to disable if yor using windows seven you should be able to this by going to your start menu then all programs-accessories-run. when your in the run program type msconfig press ok then a menu will show up go to start ups then just un-check the start ups programs that you think is not important then re-boot your computer to apply this changes.

cleaning up your hard disk and defraging can also help to speed your boot up

to clean and defrag your hard disk go to your start up menu click my computer then right click on the drive that you want to defrag and clean do to properties then you should be able to see a circle telling how much space you have left in your drive right below it is a button "Disk Cleanup" just click it then it will show up the files that needs to be cleaned up.then just click the "clean up system files"button.

to defrag just click on "tools" menu there you should see a defragment now button just click it and it will defrag you hard disk.

adding some memory can also help to speed up your pc or laptop

about the sound problem re-installing your sound card driver should be able to solve the problem but if not then contact the store where you bought your laptop and let them test it so that they can repair it for free if the problem is in the hardware