Computer won't work

I purchased AVG Ultimate this morning and installed it on my new computer. As soon as I restarted the computer, locked up. I can't use it!!  I have rebooted it 5 times. Twice I got past the sign in page, but nothing works. Please help me!!

Hello Ann,
We are sorry to know about the inconvenience caused. Please let us know the exact message you see in your monitor when you boot your computer. Did you try booting your computer in safe mode(http://avgread.me/1JwmD6g)? Thank you.