Did your system originally (when delivered) use IDT Audio? If so, Dell's site has an IDT Audio package for M6600 for Windows 7. You will need to do some work to install it. Some older drivers won't install properly in Windows 10. It may be possible to install it in Compatibility Mode. I did that recently on an 11-year-old Inspiron. The IDT Audio package would fail near the end of the installation process to Windows 10. I did the following: I launched the Windows 7 audio driver installer. It will tell you what directory the files will extract to, so make note of it. It will be something like "C:\dell\drivers\R308434". After it extracted, I opened the extracted folder in C:\dell\drivers, right-clicked setup.exe | Properties | Compatibility tab, | at the bottom I clicked "Change settings for all users" and set it to run in compatibility mode as Windows 7. Then when I tried to launch setup.exe I was blocked. I opened an elevated CMD prompt as administrator, then pasted in the path to setup.exe to run it:C:\dell\drivers\R308434\setup.exe It installed. See this explanation of using elevated CMD prompt to run blocked executables. After installation, I had to go to C:\Program Files\IDT\WDM to set various IDT audio and other executables to compatibility mode for all users, to enable the IDT control panel to run.  Also, while Windows default drivers won't include all the options of a Dell-provided audio package, they should enable sound output. Perhaps your output device is not properly selected in Windows Settings: Settings | Sound | under Output | Choose your output device in the drop-down list.
Hello, I am still using an old M6600 notebook that I ad recently upgraded to Windows 10 Professional. All is working smotthly, but I cannot get the internal IDT audio drivers to work correctly. The drivers from Windows update install, no exclamation marks in device manager, but the audio symbol in the traay shows a red X mark to it, and it says that there was some problem with the audio drivers. I actually can try to run Windows' own troubleshoot procedure, but it will not be able to fix the problem. I tried various IDT High definition drivers from the Microsoft Update catalog, and also tried the Microsoft standard high definition Audio drivers, but none of them work.   Ho can I make the IDT audio work for my old workstation in WIndows 10?
M6600 IDT audio not working, cannot find drivers