I had a black screen moment, and then Windows 7 slowed to a crawl. Can I reinstall the OS without data loss?

I use a laptop (Dell Inspiron P17F to be exact). I was browsing the internet yesterday when everything suddenly froze, then the screen went black. After a few seconds, I got an error message that went something like this: "Media test error - check cable. Operating System not found." I forced off the laptop and rebooted Windows. I thought it had worked when it booted as normal, but it had become slow as hell, took a minute to open a PDF and opening My Computer would lead to a couple of 'Not Responding' moments with Windows Explorer before I could enter D drive. I am convinced an OS reinstall is needed (although if you guys think something else can solve it, please tell me)

I have a Windows 7 re-install CD and a drivers CD that came along with the laptop. My hard disk has a C: drive (OS) and a D: drive (where I got all my anime, football vids, movies, manga and stuff). If I reboot from the CD and re-install the OS, will I lose only the program installations and data in C: drive (I can live with that), or will the D: drive be wiped clean as well? (I'll need to backup everything in that case) If D will be wiped out, is there any method of reinstall that will help me keep my movies and stuff? I'm flat broke and got no external HDD or other media to backup all 315 GB of stuff in the D: drive