Windows 7 won't boot

I have no clue what went down today. I fired up my laptop and this window just pops up out of nowhere: "your computer was unable to start......startup repair is checking your system for problems" and it’s just been spinning for like an hour straight. I tried rebooting it to get into Safe Mode, but nope—same exact headache.
Anyone here dealt with this before? Any idea how to fix this mess?

Something’s definitely off here—do you actually have a Windows 7 CD on hand now? If so, you should probably try running a Windows repair...

Yeah, I actually have a Windows 7 CD sitting right here.
I'm guessing I gotta reboot the rig, pick first boot device in the BIOS or whatever, but then I'm totally lost.
If you don't mind, could you walk me through how this works? Please!

I have sent those instructions over to you via private message.