The error you're getting means it's trying to boot the HD. You want to boot the disks: How to Boot A Computer from CD or DVD - YouTube
You're better off dumping the HP bloatware which throttles Windows 7 from it's native performance. Everything you need is here to Clean Reinstall - Factory OEM Windows 7
with the Product Key on the COA sticker for the licensed version you own to reinstall any way you please.
If you'd prefer to run the HP Recovery Disks to reinstall the worst load of crapware in the industry then first wipe the HD with Diskpart Clean Command
accessing DISKPART At PC Startup
. This will cause the Recovery Disks to autostart when you place them in the drive, one at a time in order.