Welcome to the Community,
some thoughts:
- make sure the checksum for the downloaded installation package matches (http://www.vmware.com/download/md5.html)
VMware-player-5.0.2-1031769.exe
MD5SUM: 8dceefce743be126a5e5da2731706775
SHA1SUM: b51a6575dabef1e241feba61075627ce0f9c226d - open the Windows Task Manager to ensure there's no "fixcamera.exe", "webcam.exe" or similar process. If so kill it.
- try installing VMware Player by right clicking the installation package and "Run as Administrator"
André