What version of Windows XP are you using? Home? Pro? Corporate? Have you recently installed Service Pack 2?
expand X:\i386\autoexec.nt_ c:\windows\system32\autoexec.nt
Replace X:\ with your CD ROM drive letter.
or if you don't have the CD...
To verify whether you have the file, type "%windir%/system32/" in the address bar of an Explorer window. If there is no AUTOEXEC.NT file proceed as follows:
1. Browse to "%windir%/repair/" (usually "C:\WINDOWS\repair")
2. Right-Click and Copy the AUTOEXEC.NT file
3. Browse to "%windir%/system32/" (usually "C:\WINDOWS\System32")
4. Right-Click inside the window and Paste the file
How ever the problem may persist upon rebooting...
After a Windows XP SP2 upgrade you may encounter a message about either CONFIG.NT or AUTOEXEC.NT being "...not suitable for running MS-DOS and Microsoft Windows applications." It's possible the DOS 16-bit COMMAND.COM program and/or one of those files has become corrupted if you get this message. There is another possibility as well; described below.
Microsoft has a knowledgebase article on this. What it basically says is that you need to replace the files AUTOEXEC.NT, CONFIG.NT, and COMMAND.COM which are found in your Windows System32 folder with the same-named files found on your original OEM Windows XP CD-ROM. Use the steps above for expanding from the WinXP CD-ROM.
In addition to the CD-ROM, copies can also usually be found in the \Windows\Repair subdirectory.
The replacement should be a one-time fix; however, some versions of the Windows XP SP2 update have code that will automatically delete the AUTOEXEC.NT file if found in the System32 folder on the theory that all software should be 32-bit and not 16-bit. But, you might still want or need to run older programs and will need the AUTOEXEC.NT file to do that.
If this happens to you try copying the AUTOEXEC.NT file to the System32 folder under the Windows folder and then right click on it, select Properties, and check the Read Only attribute. This should work.
If it does not you will have to recopy the file to the proper directory after every restart of the computer. While a pain in the ass, you can automate the process using a batch file with a little work.
First, make a copy of the AUTOEXEC.NT file in a directory of its own on the C: drive (I'll assume it's in C:\MS_SUX\AUTOEXEC.NT for this example ). Make the file read only (right click on it, select properties, check the read-only box).
Now open a text editor (Notepad will do) and copy/paste in the following lines...
Copy C:\MS_SUX\AUTOEXEC.NT C:\Windows\System32\
Attrib +R C:\Windows\System32\AUTOEXEC.NT
Save this file as C:\MS_SUX\FIXIT.BAT. Then, open an Explorer window and navigate the the C:\MS_SUX folder so you can see the FIXIT.BAT file. Right click on the file and drag it to your desktop and release. When asked, select the Make a Shortcut Here option.
Then, after each restart if the file goes missing again, all you have to do is click on the FIXIT.BAT shortcut and the file will be copied to the right place and marked read only automatically. Additionally you can place the BATCH file shortcut on your Quicklaunch bar, or place it in your Startup folder if the problem persists.
Note: Some versions of Windows XP call the Windows folder WINNT. If you have one of those, substitute WINNT for Windows in the above.
I hope this helps
I tried for hours to come up with a signature and all I came up with was this.