Parallel.Foreach + yield return?

I want to process something using parallel loop like this :

public void FillLogs(IEnumerable<IComputer> computers)
{
    Parallel.ForEach(computers, cpt=>
    {
        cpt.Logs = cpt.GetRawLogs().ToList();
    });

}

Ok, it works fine. But How to do if I want the FillLogs method return an IEnumerable ?

public IEnumerable<IComputer> FillLogs(IEnumerable<IComputer> computers)
{
    Parallel.ForEach(computers, cpt=>
    {
        cpt.Logs = cpt.GetRawLogs().ToList();
        yield return cpt // KO, don't work
    });

}

EDIT

It seems not to be possible... but I use something like this :

public IEnumerable<IComputer> FillLogs(IEnumerable<IComputer> computers)
{
    return computers.AsParallel().Select(cpt => cpt);
}

But where I put the cpt.Logs = cpt.GetRawLogs().ToList(); instruction