missing CD/DVD drive

Hi all. I'm working on the laptop from Hades again with a different prob. this time. My neighbor brought it over and said the
CD/DVD drv. worked intermittently, then disappeared altogether.

I looked it over and saw that it wasn't showing in Computer, nor Device Mgr., so I've been all over the internet and did these:
Deleted LowerFilters in Reg. Edit. (UpperFilters wasn't listed)--rebooted--no success
Physically removed and re-inserted the drv.--no success
Ran MS FixIt--no success
Booted into Safe Mode--drv. is not shown there either
Ck'd. "dumbed down" PhoenixBIOS Setup vF.34--headings were Main, Security, System Configuration, Diagnostics, and Exit. In System Configuration>Boot Options>Boot Order:

ATAPI CD/DVD ROM Drive (I can hear the drv. "bump" during bootup)
Notebook Hard Drive
USB Diskette On Key
USB Hard Drive
Network Adapter

I let it go for a few days as I had others to work on, then she showed up up with a new drv. and insisted I install it. I told
her I didn't think the drv. was at fault, but I installed it as she DID NOT want the old drv. back in it. When I booted into
Windows, it found the new drv. and was shown in Computer and Device Mgr. After testing it with different CDs, DVDs, etc., all seemed OK until I tried to install MS Works (it got about halfway thru, then just sat there--no CD/DVD drv.activity whatsoever. I ck'd. Computer and Device Mgr.--no CD/DVD again!!!!!!!

I'm not a pc expert, so I'm now at a standstill. Could someone please help me fix this issue? Thanks in advance for any
suggestions.

HP Pavilion dv9610us
1.9GHz AMD Turion 64x2
1GB RAM
Vista Home Premium 32-bit SP2