Audio Does Not Sync With Video When Downloaded Videos Are Played

[Alsatian Dad]

I have a Dell Optiplex 9010, I7 with 32 GM Ram & 500 GB HDD, on to whic I recently installed a copy of Windows 7 SP-1 from a Windows installation disk and that I was able to authenticate with Microsoft. I believe that I have a driver problem because downloaded video from You-Tube or Rumble by using Gihosoft Tubeget has audio not synced with the video. I have used the Gihosoft Tubeget software on a different Windows 7 machine and it works without difficulty. The sound is set to high definition audio and plays streaming video from websites without difficulty. The out-of-sync problem occurs with a different players including VLC. Any ideas or suggestions would be appreciated. Thank you.