Best/easiest way to convert wma files?

All done and now have over 6000 albums to explore.
Quick glances show not too many duplicate of my own collection.
Enough to last me a few evenings I would say.......

Thank the Lord for CMD batch file extension delete to get rid of all the left over WMA files on the drive.
Less than 30 seconds for the PC to wipe out 95000 WMA files , impressed!

Djones.
I have all the great suggestions saved, it is much appreciated.

Tbh, the time is no biggie as off this week and just letting it do its thing in the background.
I think flac files take up less space than wav though.
And it looks like my 239gb WMA files converted to flac is still going to overflow the 2tb hard drive!
Just bought a 4tb hard drive to transfer to later.

Using the trial version of sound forge pro as Al suggested.
First test batch of 500 went well and did exactly as I wanted.
Started the complete hard drive conversion last night, 12 hours completed, 11 hours to go... lol.

Thanks Al
Just completed a test batch of 500 converted to flac and all is well!
Reads them just fine now so.....
only 94,500 to go......