Recovery disk for SX2855-UB10P

press f8 during the boot up process then select the last known good configuration

It ius fetal error.

It means your harddisk need fix bed indexing and tyoehr thing.

For that boot your computer with bootable recovery disk.
Then g o to recovery consdole it is like command propmt.
Then type in command prompt."chkdsk /r"
then press "y"
then it fix eror on harddisk.
Then check.

Ifyou have compressed the hard disk drive using the Compress drive to save disk space option under the Propertiesmenu for your hard disk drive and have performed a non-destructive recovery ora system recovery, the following error message may appear: NTLDR is compressed. Press CRTL-ALT-DEL to restart. This error message is resolved byfollowing these steps: 1. Insert the Windows XP CD drive onthe computer and restart the computer. 2. Press F12 when the computer firststarts, then select CD-ROM, click any key to boot into windows startup. 3. When you get to the install windowsXP screen: 4. Press Rto repair the Windows XP installation using Recovery Console. 5. Enter the appropriate number for theWINDOWS installation, for example, the WINDOWS installation could be listed as 3:C:\WINDOWS or 3: D:\WINDOWS . 6. If prompted, enter yourAdministrator password and press Enter . If there is no password, justpress Enter . 7. At the prompt, if the WINDOWSinstallation you selected in Step 4 was C:\WINDOWS, type: cdc:\ Or, if theWINDOWS installation you selected in Step 4 was D:\WINDOWS, type: cdd:\ 8. At the prompt, type: attrib-c ntldr and thenpress Enter . 9. At the prompt, type: exit 10.Press the Enter key and immediately remove all discs or diskettes from thecomputer to allow the computer to restart.

The previous windows installation is either damaged, or did not complete, it is asking you to put your windows disc in so that in can proceed with the installation.
The recovery manager must have damaged your windows installation

Turn the computer off.
Turn the computer on, and look for a message like "press BLAH to enter System Recovery".
When you see the message, press the BLAH key.
This will start a complete "restore-to-factory" install of Windows.

Or, if you have a set of "System Recovery" CD/DVD disks from HP, then insert the 1st disk,
restart your computer, and select to boot your computer from the CD/DVD drive.

Or, there may be software already on your computer that lets you "burn" a set of "System Recovery" CD/DVD disks -- have 10 CD-R disks, and 5 DVD-R disks -- you may need to use most of these "blank" disks.

Since you cant start it using your recovery disk, you need to bring it to a service center because the are going to take out the hard drisk and connect it with other computer so they can do the restoration or reformating

http://h10025.www1.hp.com/ewfrf/wc/fastFaqLiteDocument?lc=en&dlc=en&cc=us&docname=c00220758&product=12455
If you have compressed the hard disk drive using the Compress drive to save disk space option under the Properties menu for your hard disk drive and have performed a non-destructive recovery or a system recovery, the following error message may appear: NTLDR is compressed. Press CRTL-ALT-DEL to restart. This error message is resolved by following these steps:

1. Insert the HP Recovery Tools CD or Compaq Recovery Tools CD into the CD drive on the computer and restart the computer.Wait for the HP Recovery Tools CD or Compaq Recovery Tools CD window to open.
2. Select Run Microsoft Recovery Console , click Next , and then follow the onscreen instructions. NOTE: If you are unable to open a recovery console, follow the Alternate steps .
3. Press R to repair the Windows XP installation using Recovery Console.
4. Enter the appropriate number for the WINDOWS installation, for example, the WINDOWS installation could be listed as 3: C:\WINDOWS or 3: D:\WINDOWS .
5. If prompted, enter your Administrator password and press Enter . If there is no password, just press Enter .
6. At the prompt, if the WINDOWS installation you selected in Step 4 was C:\WINDOWS, type: cd c:\Or, if the WINDOWS installation you selected in Step 4 was D:\WINDOWS, type: cd d:\
7. At the prompt, type: attrib -c ntldr and then press Enter .
8. At the prompt, type: exit
9. Press the Enter key and immediately remove all discs or diskettes from the computer to allow the computer to restart.The error message should be resolved.

Alternate steps NOTE: These alternate steps work for HP and Compaq desktop PCs with Windows XP and a recovery partition. (M0st HP and Compaq PCs with Windows XP have a recovery partition on the hard disk drive.) These steps do not work if you have replaced the hard disk drive, replaced Windows with another operating system, or repartitioned the recovery partition.You can use the following steps if you are unable to open a recovery console:

1. Turn on the computer. When the initial logo screen appears, press the F10 key repeatedly until a message about starting recovery appears.
2. At the Recovery screen, click Advanced Options and then press the Alt and D keys at the same time to go to a command prompt.
3. At the command prompt, enter the following: diskpart
4. At the command prompt, enter the following: list volume
5. Remember the drive letter next to line for the main hard drive; HP_PAVILION or PRESARIO.
6. To close Diskpart, enter the following: exit
7. At the command prompt, enter the drive letter followed by a colon (:). For example, H:
8. At the command prompt, enter the following: cd \windows\system32
9. At the command prompt, type the following: compact ntldr /u <the drive letter>:\ntldr For example if the drive letter was H, you would type: compact ntldr /u h:\ntldr
10. Type exit and press Enter .
11. Click Quit .The error message should be resolved.

Solution: Rename the C:\WINDOWS\SYSTEM32\CATROOT2 folder to something such as catold to prevent WinXP's Setup program from locating the folder and halting the installation. If you are still in Setup, press SHIFT-F10 to launch a command prompt from within Setup. At the command prompt, type cd\win dows\System32 to open the System32 folder and then type rename CATROOT2 catold, press ENTER, restart the computer, and attempt the upgrade again.

If you cannot reach a command prompt from Setup, reboot the computer from a Win95, Win98, or WinMe startup disk and rename the folder from the command prompt. You can also launch a command prompt by booting from the WinXP installation CD and running the Recovery Console.

You need the disk, it needs to replace the damaged files, Is this an XP system. Any disk will work to repair it but you have to have your Origianl to re-install completely.

Once you get one, I can run your through the system repair through Command prompt by booting from disk.

Let me know and good luck.