First of all - welcome to BC !
In your next post can you please include the make and model of your computer, or, if a self-built, then the mobo, CPU and RAM. At the least, this is useful information !
Can you get into 'Safe mode' (normally by tapping the F8 key a few times after you switch on and until the BIOS screen appears) ? If you can, scroll down - using the up/down arrow keys to 'Last known good configuration' then press 'Enter'. If Win repair isn't working this may not either but it is worth a try.
If neither safe mode or Win repair work then you are probably looking at either a recovery situation or a re-install, both of which will wipe out any data of yours on the computer. You will wish to recover any data - work, photos, music, etc. - before you do this. One of the simplest ways to do this is to use a self-booting Linux CD and use the Linux system to copy all your data to external storage before you do a recovery or re-install.
This will NOT turn your computer into a Linux box since a self-booter runs entirely in RAM. I personally use Puppy for this for two reasons - (1) I have a copy on my desk, and, (2) it fits on a CD ! You can use most versions of Linux as a self-booter but Puppy is nice and small. You can get it, plus instructions, here -
It downloads as an ISO. If you are going to use it as a CD you will need to unpack the ISO before you burn it, if you need to use a USB drive the you will need to use 'Rufus' to burn the ISO to a memory stick. Google it.
Start the computer with either the CD in the drive or the USB plugged in. You may need to go into the BIOS to change the boot priority order so thet either the CD or the USB is first, whichever you are using, and the computer should just boot . It is then merely a matter of plugging in some external storage big enough to take your data and copying it across to it.
If you have any more questions on this procedure, post back. Somewhere down the line you may get the lecture on the advantages of having a back up policy in place !