Windows 7 Help Needed: Troubleshooting Blue Screen Errors and Potential Hard Drive Failure

Hi ,
My hubby's computer died this morning. It's giving me blue screens - bad pool header errors - can not reference memory and write memory errors. His hard drive is 5 years old. He is running win 7 home pro 64bit. I "think" its an AMD processor - not really sure but can check. I tried running the repair utility and could not. I tried inserting the DVD and running it off of it and could not. I tried to re-install and can not. When I click the install button I'm getting - "can not write referenced memory errors. Am I waisting my time with a corrupt hard drive? Any help is GREATLY appreciated - beyond belief !!!! Thank You for your time and help !!!
Best Regards Melissa R Lang