Strange Funny Error on my PC

Hello guys,
I need a quick and urgent help. Since this evening, I am having a strange error that disturbs me a lot. As soon as I start my personal computer, a windows appears that says.

P and F Fan
Windows has detected that you are not a Phineas and Ferb fan. Please erase your hard drive.
Cancel Erase hard drive
The cancel button is disabled and the only button that is able is the erase hard disk one.
I cannot allow me to do any thing else, so I can’t get rid of that except forcefully restarting the system by the restart hardware button or power off button.
This installation contains my lot of precious data and I cannot afford loosing that.
Please suggest me the measure.
Thanks.
