Windows 7 restarts when booting safe mode

[Ben Sparrow]

My PC launches into windows normally but I want t get into safe mode. As my computer is launching I hit F8 and I press the option to launch in safe mode. It takes me to the login screen and then restarts again. Why is this happening? Can someone please help?

 

[Paul NZ]

Could be something in startup causing it. Altho it would do it, if you booted into windows normally too