You probably have realtek AC97 audio driver installed in your Compaq Presario 700 Notebook laptop. and it is not producing any sound. Though, it's worked properly before after some time you find out there is no sound coming from the speakers. Severally, without result you have tried to reinstall the sound driver for the system but to no avail. From be exhausted of all information available at your disposal this last resort will solve the problem.In a nutshell, it is something that has to do with the system manufactural genuine sound driver requirement.
Step 1: Uninstall any audio driver in your compaq presario 700 notabook by going to the Control panel. Click Start --> Control panel --> Add/Delete programs and look for realtek ac97 audio driver or any other audio driver installed before and uninstall them.
Step 2: Click Start --> Execute --> type dxdiag into the box and ENTER. Search for the System model and write it down.
Step 3: Download ccleaner from Ccleaner Official Website and clean up your registry editor .
Step 4: Go to Compaq Official Website to download drivers for 700AE Notebooks ADI SoundMAX Audio Driver for Microsoft Windows XP.
Step 5: Restart your computer and the sound will come up this time.
Step 6: If there is still no sound, try and uninstall the SoundMax through the control panel and repeat STEP III to V.