Sound strobing in my acer 5330 i tryed external sound card and external hard disk and reinstalled windows and drives and the sound still strobing

Try this method it may work.
If you can boot up with the external USB hard drive on your Acer, then use a working computer and copy the Windows installation CD onto the external hard disk then connect the USB externak hard disk to the USB port on your Acer and boot up using the external hard drive.

The Aspire One is a netbook produced by Acer; it does not come equipped with a CD ROM drive, so a traditional hard drive reformat and Windows reinstallation is not possible without a peripheral storage device. An external USB CD or flash drive will suffice, however.Difficulty:Moderate

Instructions

1. • 1 Plug in the external CD drive, then turn on your netbook and let it boot to your operating system.
     
   • 2 Open your web browser and go to the BootDisk website (see link in Resources). Download the Windows XP Fresh Install Bootable CD, then burn these files to a blank CD via your external CD drive.
     
   • 3 Ensure the files have burned to your bootable CD, then restart the netbook with the CD still in the drive.
     
   • 4 The netbook should boot to the CD upon the restart. Follow the instructions prompted for installation. Upon completion you will have a clean installation of Windows XP on your Acer Aspire One.
     

http://www.piriform.com/

try running ccleaner, download and install from above web page.
run the cleaner to delete old files and clutter, run registry to tune windows.
In tools section go into start-up and disable all programs, and then any programs that need to start on switching on will still start, but normally lots of other programs start up that dont need to, stopping these from starting up will speed up your laptop. Don't woory about disabling programs, when you want to use them they will start as normal

change boot order to the disc/usb that has the recovery on. don't let it boot from hard drive.

Turn the computer on.
Press F8, repeatedly, until you see a start-up menu.
Choose "safe mode".

If it boots, open All Programs.
Open Accessories.
Open System Tools.
Open System Restore.
Select a date/time when your computer _was_ working correct, and go "back" to that checkpoint.

If that does not help, and it boots, use the Windows XP/Vista/7 "File and Settings Transfer Wizard" to create one file, holding all your E-mail, contacts, and music files.
Copy that file to an external disk-drive.

Then, take a deep breath, and reinstall Windows.
Reinstall MS Office.
Reinstall your anti-virus software.
Reinstall Adobe Reader.
Reinstall your other program.
Finally, reload from the external disk-drive.

A "best practises" approach should be taken:

1. backup all your E-mail and files and music to an external disk-drive.
2. reinstall Windows from "genuine" Microsoft CD-ROMs.
3. reinstall your anti-virus software.
4. run Windows Update, several times, to get all the security-updates.
5. reload from your "backup" external disk-drive.

You have a corrupt Windows system configuration/registry. Someone else chime in if there is hope, but my only solution (given it won't start up in safe mode) is to wipe and reinstall.

You don't need a driver.


The best way to download pictures from your camera to your computer involves removing the memory card from the camera and plugging it into a card reader (either built-in to the computer or connected via USB or FireWire). This is likely to be faster than connecting the camera to the computer, and won't run down your camera's batteries.


Once the card is plugged in, it will appear to your computer as a removable drive. You can use the operating system's drag&drop facility to copy pictures from the card to the computer's hard drive, the same way you copy any other files. Or you can use any photo cataloging program such as Picasa.

Actually you need to install chipset drivers first then you shoud try for additiona PCI driver like external sound card.
Try one thing again, go to your www.acer.com site and search driver as per your "Service tag no." not for model no. and download drivers for 'Chipset' and others as per your requirement.

Thanks
Iqbal