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Get the fix to the boot-time error message <strong>"Invalid BOOT.INI file Booting from C:\Windows\"</strong> and other BOOT.INI problems affecting Windows XP.
<h2>About "Invalid BOOT.INI file"</h2>
[kbintro]
<h3>Description and Symptoms</h3>
The error messages, alerts, warnings, and symptoms below are tied to this error.
<h4>Symptom 1: Invalid BOOT.INI file</h4>
Boot.ini, a critical component <a title="Windows XP Boot Components" href="http://neosmart.net/wiki/windows-xp-boot-process/">of the Windows XP boot process</a> responsible for maintaining a list of installed operating systems and what partitions they are located on, must be correctly configured for successful boot up of Windows.

In cases where boot.ini is misconfigured, incorrect, corrupted, or unreadable, the following error may be seen when attempting to start the PC:

<img class="alignnone size-full wp-image-1565" src="/wiki/wp-content/uploads/sites/5/2013/10/Invalid-boot.ini-file.png" alt="Invalid boot.ini booting from c:\windows\system32" width="980" height="250" />
<pre>Invalid BOOT.INI file
Booting from C:\windows\</pre>
It is important to note that this error may or may not be accompanied by a complete boot failure.

If Windows is located at C:\Windows\ then this "Invalid boot.ini file" message may only flash briefly on the screen before your PC proceeds to boot into Windows XP.
<h3>Causes of this Error</h3>
This error has been known to occur as a result of one or more of the following:
<h4>Cause 1: Misconfigured boot.ini file</h4>
BOOT.INI is the configuration file for the Windows NT bootloader, NTLDR (also used by Windows XP and Windows Server 2003).

The "language" or format of the boot.ini file is standard and the same as any other .INI configuration file, with section headers in between <code>[square brackets]</code> and the actual configurations settings on the lines that follow.

If these rules are violated, for example the boot.ini file cannot be parsed as an INI file, the <code>[boot loader]</code> section is missing or misspelled, the boot.ini is empty, etc. this message can be displayed.
<h4>Cause 2: [operating systems] is blank</h4>
A correctly-structured boot.ini with the correct <code>[boot loader]</code> and <code>[operating system]</code> sections may cause this boot exception to occur at system startup if the contents of either of these two sections are empty.
<h4>Cause 3: Incorrect ARC paths</h4>
One reason why boot.ini has always been very difficult to edit and maintain is the arcane nature of the references to the Windows partitions.

While syntax like <code>C:\Windows="Microsoft Windows"</code> is technically valid for some versions of Windows XP and NTLDR, it is more common to see ARC paths used in boot.ini, as is described in the comprehensive boot.ini knowledgebase article.

If these ARC paths are not in the correct format (example: <code>multi(0)disk(0)rdisk(0)partition(1)\WINDOWS</code>) or point to an invalid or incorrect partition, this error can be displayed.
<h4>Cause 4: Boot.ini in UTF-16/UCS-2 or other non-ASCII encoding</h4>
One of the undiscovered causes of "invalid boot.ini" messages stems from the usage of double-byte <a href="http://en.wikipedia.org/wiki/Unicode" rel="nofollow">Unicode</a> encoding for the contents of the boot.ini file.

Without getting into extensive details, the encoding of a text file determines how the letters of the text file are stored on the disk in binary format. Most versions of NTLDR only support an ASCII-encoded boot.ini file.

Later versions of NTLDR shipping with updated releases of Windows XP SP2 or SP3 and Windows Server 2003 R2 can read boot.ini files encoded in <a href="http://en.wikipedia.org/wiki/UCS-2">UCS-2</a> or <a href="http://en.wikipedia.org/wiki/UTF-16" rel="nofollow">UTF-16</a> as well.

The presence of a BOM (byte order marker) in the text file will also cause NTLDR to be unable to read the boot.ini as it is saved to the disk, and the "invalid boot.ini file" error will be seen.
<h4>Cause 5: Boot.ini has been compressed</h4>
As with other critical boot files, BOOT.INI must be saved to the NTFS or FAT partition without any compression whatsoever. Unlike when Windows is booted, during the bootloading procedure a very restricted version of the NTFS or FAT32 driver is loaded, and is incapable of reading dependency files that are compressed, zipped, or fragmented.

Use of disk compression tools like DoubleSpace and DriveSpace or manually enabling file and folder compression on the boot partition can cause errors reading and loading boot.ini, resulting an a computer that will not start or boot.
<h2>Fixing "Invalid boot.ini file" on Windows</h2>
[setupcd]
<h3>Fix #1: Rebuild BOOT.ini via Easy Recovery Essentials</h3>
Easy Recovery Essentials' one-click automated system repair feature incorporates full repair and reconstruction of boot.ini to resolve the "invalid boot.ini file" error, even in cases where Windows won't boot as a result of the error.

The automated boot repair component of EasyRE will address all boot.ini-related issues, including correctly boot.ini files using the incorrect encoding and correctly identifying the appropriate ARC path for the boot.ini entries.

This will also take care of a compressed or fragmented boot.ini.

[easyre error="Invalid boot.ini file" bootscreen="xp" guaranteed="true"]
<h3>Fix #2: Manually attempt recreation of boot.ini</h3>
If boot.ini is incorrectly configured, does not contain the correct or expected contents, or is in a format that NTLDR cannot understand, the following steps on manually recreating boot.ini may help.

Note that these steps may not resolve "invalid boot.ini file" errors if boot.ini has been previously compressed or fragmented, in which case the above EasyRE instructions should be employed instead.

[partial name="partial_bootini"]

[caption id="attachment_4997" align="alignnone" width="720"]<a href="https://neosmart.net/blog/wp-content/uploads/sites/5/2013/10/Bootcfg_rebuild.png"><img class="size-full wp-image-4997" src="https://neosmart.net/blog/wp-content/uploads/sites/5/2013/10/Bootcfg_rebuild.png" alt="Bootcfg utility results screen" width="720" height="396" /></a> Bootcfg utility results screen[/caption]
<h2>More Information</h2>
<h3>Linked Entries</h3>
The errors below have been verified as being associated with or related to this problem:
<ul>
 	<li><a href="http://neosmart.net/wiki/ntldr-fatal-error-boot/">Fatal error reading boot.ini</a></li>
 	<li><a href="https://neosmart.net/wiki/bootcfg/">bootcfg</a></li>
</ul>
[partial name="partial_moreinfo" versions="xp,server2003"]