I get the following error message when starting my laptop.
"Error Loading Explorer.exe. You must reinstall Windows"

What should I do?

from: http://support.microsoft.com/default.aspx?scid=KB;EN-US;q299296

To resolve this issue, replace the Msvcrt.dll file with a new copy from the Windows CD.

1. Restart the computer using a Windows Millennium (Me) Startup disk.
2. At the Windows Me Startup menu, type 2, and then press ENTER.
3. Record the drive letter that is assigned to the CD or DVD-ROM drive.
4. Type ext, and then press ENTER to start the Microsoft Extract Command Line Helper starts.
5. At the Please enter the path to the Windows CAB files (a:): prompt, type drive:\win9x (where drive is the drive letter that you recorded in step 3), and then press ENTER.

Note: Depending on your installation of Windows, the Windows .cab files may also be stored in the \Windows\Options\Install folder.
6. At the Please enter the name(s) of the file(s) you want to extract: prompt, type msvcrt.dll, and then press ENTER.
7. At the Please enter the path to extract to ('Enter' for current directory): prompt, type c:\windows\system, and then press ENTER.
8. At the Is this okay? (y/n) prompt, type y, and then press ENTER to extract the file to the specified directory.
9. Remove the Windows Me Startup disk, and then restart the computer.

Thanks, but what do I do if I do not have a Windows Startup Disk?

If you go to add/remove programs on the control panel you should have the option of creating one. it's on the startup disk tab.

I typed in ext and it says that is a bad file name

so you pressed 2 on the menu, presed enter, and then typed ext?