I haven't read every single post about this error, but here's what worked for me.
Make sure that the clocks are synced on all computers that you are networking. I know it sounds crazy but it has be done.
Of course you do that with the time/date dialogue in the taskbar.
Jim
I almost went crazy trying to homegroup two computers until I came across this fix.
I know this thread is very old. Its not going worth post here anything.
But I want to say that, your solution is 100% working. None of the other results in google have the solution to this problem.
You made my day
Thanks.
System Manufacturer/Model Number Assembled OS Windows 7 Ultimate x64 CPU Intel Core i5-2500k Motherboard Intel DH67CL Memory 4GB-1333MHz DDR3 Monitor(s) Displays 21" Screen Resolution 1280x1024