Booting problem on HP dc7900 USFF

I had purchased 2 of these units and a new HDD and loaded win7 which works fine but when I power on, after POST I am getting a screen with "ntldr is missing", I restart choosing the boot order screen, sometimes I am not seeing the HDD listed and sometimes it shows, when I go to the BIOS I can select the HDD as first boot and then it boots to windows. I had suspected the HDD may be at fault so I tried another new HDD, same deal then I tried everything on the 2nd identical machine but same deal on BOTH machines so I am thinking it is definitely these unit's systems and not the hard drive as I have just reloaded the OS on a 3rd new HDD and same deal, there has to be a way to fix this?

I tried asking for help on the HP form but no replies. I am thinking I may need to update the BIOS? If so, this is the link to HP's site for the update but I am not sure exactly which to choose, help please?

http://h20565.www2.hp.com/portal/si...tlet.endCacheTok=com.vignette.cachetoken#BIOS

 

I would do the newest bios update Mike, too bad they don't say what the various bios updates fix as I don't like to do them unless I know what they are for however this sounds like a bios and/or motherboard issue so you have no choice but to start with bios upgrades. Can you tell us a little about this purchase and it wold also help to have the model number of the pc so we can look at it as well. Sounds like something happened to these units so I would be a little suspicious as that is not normal behavior.

 

Didn't work Cindy. I got one of the first units from a friend's corporate office here in Manhattan when they were upgrading so they had taken the HDD out, after having this problem I decided to try another unit so I found them selling on ebay where I purchased the 2nd unit so both did not come from the same source.

 

One guy told me it might be the cmos battery failing but on both units?

 

Very possible Mike and easy to prove. Another one is bad cable or bad psu plu or unit as they all could contribute to that and these units have amongst the worst psus known to man.
Another thought is rest the bios to optimum defaults, believe it or not this is a known problem with these units:
http://www.bleepingcomputer.com/forums/t/524883/booting-problem-on-hp-dc7900-usff/

 

Damn, just to "try" a cmos battery will cost me $25 from HP as I cannot find any online.

 

I like to think I am very good at net research Rich, I can't come up with one typing "hp dc7900 cmos battery" or by typing the part no. which is hp 244556-001 ?

 

Now this is much better:

http://www.ebay.com/itm/like/261335926882?lpid=82

Thank you very much, I will order it and let you guys know what happens, till then, a very Happy Easter to all!

 

Mike did you read my post #7? I think the bios set to Optimum defaults will fix it.

 

Yes Rich, i had tried that, no change.

 

I have a couple of questions Mike. Forgive me if I've misread some of the posts above and missed something.

1) Are you using the same Win 7 install disk on both computers, or two different disks?

2) When installing Win 7, are the HDD's you're using brand new or second hand?

3) Do you have just a single HDD in each machine/computer?

4) Are you going to, or have you done a custom/clean install on both computers? (This is what you should do)

5) If the HDD's are second hand, are one or both of them partitioned?

6) Where did your Win 7 install disks come from? (Please be honest answering this question)

And just to add what has already been stated. It's a good idea to replace the CMOS batterys. The battery you need for a desktop computer is a CR2032-3V.

And for those that want to know...
The C means that the battery is a lithium electrode organic electrolyte manganese dioxide electrode type.
The R simply means that the battery is round.
The first two digits (20) represent the diameter of the battery in millimeters. 20mm
The second two digits (32) represent the thickness of the battery. 3.2mm
3V stands for 3 volts.

 

No worries, always appreciate any help at all, please see my answers to each question below and thanks for the detailed explanation on the Cmos battery!

I have a couple of questions Mike. Forgive me if I've misread some of the posts above and missed something.

1) Are you using the same Win 7 install disk on both computers, or two different disks?
I tried 2 different disks.

2) When installing Win 7, are the HDD (Hard Disk Drive)'s you're using brand new or second hand?
I tried both new and used on both units.

3) Do you have just a single HDD (Hard Disk Drive) in each machine/computer?
Not sure I understand this question?

4) Are you going to, or have you done a custom/clean install on both computers? (This is what you should do)
Custom/clean install after reformatting the drives.

5) If the HDD (Hard Disk Drive)'s are second hand, are one or both of them partitioned?
Both drives are not partitioned.

6) Where did your Win 7 install disks come from? (Please be honest answering this question)
I have a friend with a local store here, he had given me a disk set with all OS for both pc and mac. I always use this to install on anyone's unit then use their product key to activate, I have never had any issues with my disks before so that definitely is not the problem.

 

Oh BTW, I also tried Vista, same deal.

 

The question you don't understand Mike is really more simple than you think and that is does each pc have only 1 hard drive in it.
This is a real tough one Mike so we need to think outside the box and use what we know about this unit which is basically a slimline. It has a defect which is a very poor psu but
I don't see what that has to do with anything you are seeing. So then lets look at what affects an install of Windows then. Bad hard drive, bad dvd, bad dvd drive and bad memory all can play havoc with a Windows install.
As much as I cannot justify it I would next run memtest86 on memory from www.memtest.org and do at least a full test of 8 passes before ruling this out. Try another dvd drive and you don't have to remove the one in there just somehow plug in another drive externally or maybe try a usb dvd drive if you have one. I think you have used enough hard drives and disks to satisfy that thought especially since you state you also tried Vista.
If it isn't any of the above then we almost have to assume the motherboards are both bad, crazy as it sounds and you can try by removing all ram sticks and trying to boot and see if you get the three beeps from Hell for ram missing which means the board is also OK somewhat. Of course the system would have to have a motherboard speaker to get the beeps which most systems have. And one way or another we arrive at the boards being bad anyway as that is all that is left.
Ooh another thought, are you using 32 bit or 64 bit dvdsbecause I would bet 64 bit will not work on this unit?