Windows 7 important files fail to open and does not login

Hi

My laptop has been running fine for the last 12 months.

when i switched it on today the login screen appears when i enter my password it logs in and logs me back out. the same goes to safe mode.

Now as I have another partition with windows 7 I managed to get in there but any important windows files fail to open such as regedit and system restore and many many other files fail to open. It keeps saying the file could not be found

I tried sfc /scannow but it says i need administrator permission when I am already and administrator

All my important work is on my main windows 7 and canot login .

Can anyone advise what to do please

Can anyone help with this?

All i am getting is a blank screen with a cursor

Work through the steps for Troubleshooting Windows 7 Failure to Start.

You may need to work in the boot mode until you can get into Safe Mode or to the desktop.

You can also rescue your files at any time to delete all partitions during a Clean Reinstall Windows 7