I am getting "lse.exe error the endpoint format is invalid" when trying to boot up my laptop.?

I read I should boot up in safe mode by hitting F8. Well when I do it again tries to boot up windows but ends back at black screen with that same error message box. Can someone help me? I need simple instructions, perhaps step by step. I'm not very computer savvy but not an idiot either, I can follow instructions. Please any help would be appreciated, I'm hoping not to have to take my laptop to a professional because I cannot afford that and I don't want to lose everything I have on it. Also, I do not have the windows XP cd.