Hp pavillion a815n stuck after resizing partition

The advice from Post #8 still stands - just test for SATA instead of IDE: try different ports, cables, power connectors. Reset BIOS defaults.

I do not have a clear idea of what you have done and what the result of the tests were. It's hard to help being kept in the dark.

You say that "It looks like the BOOT issue is back once i connect the hard drive". Lets restart there.

Most likely the Master Boot Record (MBR) or the Master File Table (MFT) was corrupted during the partition resizing. You can try and repair these.

The first way is to use the Partition Wizard bootable CD. Boot from it and choose "Rebuild MBR".

or

Boot from a Windows 7 Installation Disk, navigate to Repair Options, and run "Startup Repair" 3 times.
(See Post #4 for more info)

Did you do either of these things?
What were the results?

What do mean by "it will not get past the boot screen"?

Do you see the BIOS screens when you start your computer (white text on a black screen)?

If so, do you see a message that says "Press any key to boot from CD..." ?

Did you press any key?

Then I would suspect you do not have the CD-ROM set as the first boot device in the BIOS settings.

If it is not set as the first boot device then the system will try to boot from the hard disk and get hung up.

If it is set as the first boot device then that means you may have burned a bad ISO, or the CD/DVD drive is faulty.

Does you W7 installation disk boot if you start the computer with it in the CD drive (with the CD-ROM set as the first boot device)?