Windows take too long too start!

I have windows 8 installed , when ever i switch on my laptop its take almost half an hour or 45 minutes to get the windows started ! It says repairing windows etc !

it works fine later when it starts and there is no load on C drive !

What to do ?

test your hardrive...then if no bad sectors found, reinstall windows... problem with either MBR or bad sector....

Better to know what is the specification of your laptop.
Try CHKDSK it is solution to 90% problems.

Might as well start over from scratch. Format your hard drive completely (after backing up your important information) and either install Windows 7 or if you want to take your chances again, try a different copy of Windows 8.

Its possible that the copy from which you installed Windows 8 may had corrupt files.