Computer reboots in a loop

I am working on a Compaq Presario SR1911X running Windows XP. The person was on the internet the computer froze and when they went to restart they were at the boot menu but not able to enter Safe mode or any of the other options. When any option was selected the computer just started to reboot in a loop.

The Bios recognizes the drive and I have it as the Primary boot drive.

So we figured the hard drive. It has a SATA drive 320 GB, so we purchased a new WD 320 GB SATA replaced it using the new SATA cable and tried a different power connection to be sure. The WD cd allowed to format the drive to the
320 GB size then we started the computer with a new Windows CD and it loaded the drivers and then asked to set up
Windows xp, it went thru the first setup procedure installing the windows files and on the first reboot it started the loop again and would not boot or go back to finish the drive setup.

So, we thought try a repair over the installation, it acknowledged that Windows was on the partition and so we told it to install over the partition. We removed the CD and it just keeps rebooting in a loop. It only stops and does anything when the Windows CD is in the drive.

I swapped out the memory and had the same results. I had the SATA be the only drive connected, the same result.
The cpu fan is spinning.

I disconnected the SATA and hooked up a known good IDE drive and the same thing, the computer booted in a loop.

So, I am wondering faulty power supply or motherboard? The power supply tester shows up good except the -5V does not light up, but that seems to be common in some towers.

Any help would be greatly appreciated. Thanks !!

Turn it off
Remove the cover
Start the computer & observe the CPU fan to see if it is working properly.
Also look for a loose chipset heatsink.

It sounds like the unit is overheating & restarting to prevent damage.

Hi fairjoeblue,

Thanks for your reply. The cpu fan is working properly. And everything looks to be seated properly too. I was thinking about the overheating, but when the Windows cd is in the drive the computer stays on to format the drive and then begin the setup process, which takes some time and it didn't have problems shutting down, just after it restarted to finish the installation the computer started to loop again. But if a Windows cd is in the drive it will stay on. They said it was dusty before I got there but they cleaned it, with a vaccume unfortunately, I told them it wasn't a good idea, but the problem was existing before they vaccumed.
Thanks for your suggestions.

I just installed a known good PSU and no change. It is looking like the motherboard I think.

Edited by Crizz44, 11 February 2009 - 04:28 PM.

" just after it restarted to finish the installation the computer started to loop again. But if a Windows cd is in the drive it will stay on. "

When you are installing XP during the install the computer will restart.
Don't press a key to boot from the CD, just let it go on it's own.
Also leave the disk in the drive as XP isn't installed yet.
Let it do what it's going to until you actually get to the desktop.
Then remove the disk.

It never ask for the "hit any key boot to cd" , it automatically uses the cd and goes to the setup. I thought that was strange too. So, if I leave the cd in and just let it restart it goes straight to the setup again, I don't press any keys.
If I take the cd out I get the restart loop.

Also I read another suggestion on another topic and it mentioned to try a new battery on the motherboard. I had a new battery, so I have also put that in. No change.

Edited by Crizz44, 11 February 2009 - 05:17 PM.

The computer is supposed to reboot & finish the setup.
Follow this & see if it helps,

Turn the unit on and put the XP disk in the drive.
Leave the disk in the drive and restart the unit,
Watch the screen for a message that says "Press any key to boot from CD,
Press a key on the keyboard,
Wait while it goes through starting from the disk,
When you get to the screen with the box that shows the current version of XP installed press "D" on the keyboard,
Press "Enter"
Press "L"
You now should have a screen asking what file system you want to format to, NTFS should be selected by default,
Press enter,
The disk will be formatted and the installation will automatically begin when the format is finished,
During the installation the computer will restart DO NOT press a key to boot from the CD again !
At that point the unit will boot from the hard drive and continue the installation.
After awhile you will be asked to "name" your computer,
I suggest naming it the same as the main user ID you are going to use.
[Example, I have an XP unit named "testbox" the user name is also "testbox"
You will be asked if you want to turn on automatic updates, select NO or Not now,
You will be asked if you want to setup a network connection, click on skip,
You will be asked to enter a user name and password,
Enter the same name you used for the unit ,
Only enter a password if you want to have to log on every time XP starts,
[If you have more then one user you can enter passwords later]
Follow the prompts to finish.
When you get to the desktop the only icon showing will be the recycle bin
Click on the "Tour XP balloon [or icon in the taskbar by the clock] and click "Cancel"
Go to Start>Control Panel,
Double click "Taskbar and Start Menu"
Click on the "Start Menu" tab
Put a dot in the circle by "Classic Start Menu"
[That will put the icons on the desktop]
Click OK
Double click on "Folder Options"
Click on the "View" tab
Go down the list until you find "Show hidden files and folders"
[for future use]
put a dot in the circle by it
Click OK
Close the Control Panel
Double click on "My Computer"
Right click on the "C:" drive
Left click on "Properties"
Click on the "Tools" tab
Click on "Defragment Now"
Defrag the drive
When you are done start installing your other programs and applications
[Defrag again when finished]
When they are installed if you have the "activate XP" notice do the activation,
When you have gotten this far either go to Windows Update and do the updates or set it to update automatically
To set it to update automatically go to Start>Settings>Control Panel
Double click on the System icon
When the box opens click on the "Automatic Updates" tab
Put a dot in the circle next to "Automaic [Recommended]
Click OK.
In order for the Automatic Updates to begin right away turn the unit completely off then restart it.

The systemboard in your model (A8n-LA) will corrupt the hard disk; but, HP's upgraded BIOS will fix it (This one drove me nuts about a year ago, too)
Here is the link to your support: http://h10025.www1.hp.com/ewfrf/wc/prodinf...product=3203112
You may have a fun time getting that BIOS flashed though as it is a Windoze utility you are supposed to use.
I take it you don't have the recovery CDs?

Thank you both for you help. The strange thing is, the computer never says, "hit any key to boot to cd", it just automatically starts the cd and installation. So, when I let it reformat and install the Windows files and it says it
is going to restart, I don't hit any keys, but it goes right back to the set up. If I disable the cd drive I get the message.
"a disk read error occurred press ctrl+alt+del to restart" This is a new WD drive. The old drive did the same thing.
The diagnostic shows the HD to be good and it shows in the BIOS.
I will try the BIOS update and see if I can do something with that.
Oh, I also tried a new SATA cable just to be sure that wasn't the problem.
I will post back. Thank you.


I don't think I can update the BIOS, I have no access to the computer and it does not have a floppy drive. Any suggestions?

Edited by Crizz44, 11 February 2009 - 07:04 PM.

I used the rcovery CD's to restore one of these about 5 times and everything would seem hunky dory for awhile and then, boom, the whole drive was corrupted! After the BIOS upgrade, it has beem solid.
You will need to restore/ reinstall afterwards.

They had what they thought were the restore cds but they did not work. I put the first one in the drive and it did not respond. They were not sure if it was the correct restore cds or not for that computer, they had other Compaqs in the past. But, I have installed a new hard drive and using a new copy of Windows XP. I am really thinking motherboard, but hate to spend the money on one and it do the same thing. But, I can't think of any other option. Thanks again.

The original drive still has the recovery partition on it. If you have backed up their data, put it back in and hit the F10 key several times before Windoze boots. For me, at least, this always worked but it was the BIOS upgrade that fixed it getting gescrewdefay again.

They have the original drive, I guess we need to get it backed up first and then give that a try. Thanks !

Well, they want to go with a new motherboard, so I will let you know how that works. I ordered it today for $60, so hopefully it will fix the problem.
Thanks for everyones help and I will post back the results of the new Motherboard.