http://support.microsoft.com/kb/287563

RtlGina2.dll

Problem
Winnt_root\System32\Hal.dll missing or corrupt:

Please re-install a copy of the above file.

Windows could not start because of a computer disk hardware configuration problem.

Could not read from the selected boot disk. Check boot path and disk hardware.

Please check the Windows documentation about hardware disk configuration and your hardware reference manuals for additional information.
Windows NT could not start because the following file is missing or corrupt:

Winnt_root\System32\Ntoskrnl.exe

Please re-install a copy of the above file.

Cause
This behavior can occur if any or some of the following conditions are true:

• The Default value in the [Boot Loader] section of the Boot.ini file is missing or invalid.
• Windows XP is not installed in the location specified in the Boot.ini file.
• The Ntoskrnl.exe file is missing or damaged.
• The partition path in the Boot.ini file is not set correctly.
• General hardware failure.

Solution
Method 1
Edit the Boot.ini file to restore or correct the Default entry and to ensure that the other entries in the [Operating Systems] section of the Boot.ini file point to the appropriate directories.

For more information about how to edit the Boot.ini file, click the following article number to view the article in the Microsoft Knowledge Base:
289022  How to edit the Boot.ini file in Windows XP
Method 2
Use the Bootcfg utility in the Recovery Console to correct the Boot.ini file:

1. Use the Windows XP CD-ROM to start your computer.
2. When you receive the message to press R to repair Windows by using the Recovery Console, press the R key.
3. Select the Windows installation that you want, and then type the administrator password when prompted.
4. Type bootcfg /rebuild, and then press ENTER.
5. When the Windows installation is located, the following instructions are displayed:

Add installation to boot list? (Yes/No/All)
[Type Y in response to this message.]

Enter Load Identifier:
[This is the name of the operating system. Type Windows XP Professional or Windows XP Home Edition.]

Enter OS Load options:
[Leave this field blank, and then press ENTER].

After you perform the preceding steps, restart the computer, and then select the first item on the boot menu. This should allow Windows XP to start normally.

After Windows XP has successfully loaded, the Boot.ini can be modified to remove the incorrect entry.

For more information about how to edit the Boot.ini file, click the following article number to view the article in the Microsoft Knowledge Base:
289022  How to edit the Boot.ini file in Windows XP
Method 3

1. Start the computer by using your Windows XP CD-ROM. Press any key to boot from the CD.
2. After the setup files are finished loading press R to repair using Recovery Console.
3. When you are in the recovery console, select the installation to log on to (usually number 1), and then press ENTER.
4. Login to the Administrator account by typing the password for this account, and then press ENTER.
5. At the recovery console command prompt, type the following command, and then press ENTER: 
   
   For Uni-Processor systems:

expand <cd-drive>:\i386\ntoskrnl.ex_ <hd-drive>:\Windows\system32\ntoskrnl.exe

For Multi-Processor systems:

expand <cd-drive>:\i386\ntkrnlmp.ex_ <hd-drive>:\Windows\system32\ntoskrnl.exe

Note In these two commands, the <cd-drive> placeholder represents the drive letter of your CD drive, and the <hd-drive> placeholder represents the drive letter of the hard disk on which windows is installed.

6. If you receive a prompt to overwrite the file, press Y.
7. Type exit, and press ENTER at the command prompt.

Method 4
Start the computer by using the Recovery Console, and then run theCHKDSK /rcommand.

Note You do not have to include the /p switch in the Chkdsk command-line because the /r switch causes the Chkdsk utility to locate bad sectors and recover readable information. This command implies the /pswitch..