I tunes launches but then will not respond after downloading new version

I Tunes launches but will not respond after downloading new software version. I have an HP with 1TB memory and 8GB Ram/ I have Windows 8. I had an automatic download this morning and I did as directed. Afterwards, I launched I-tunes and the song library appeared but the program was unresponsive with the blue thinking circle continuing for more than ten minutes until I restarted the computer. After restarting, I again launched I-tunes and the result was the same.