When rebooting my Win NT 4.0 system after installing an Internet Explorer update, I got this message:

OS Loader V4.01
.Disk I/O error: Status=00000001

Windows NT could not start because the following file is missing or corrupt:

<winnt root>\system32\ntoskrnl.exe.
Please reinstall a copy of the above file.

I do not have any backup or system disks. Is there any way to fix this problem? I need access to the data on that computer immediately and I do not have any backups

Any advice would be greatly appreciated

Sounds like a bad hd, hd corruption, or memory problems.

Since you say it happened after installing an update I'm leaning more towards HD problems.

If you had WinPE/Bartpe/NTFSDos

you could boot from those and copy over the files and chkdsk the HD.

If you do not have those tools then likely the easiest solution would be to stick the HD in another NT4 system, chkdsk the HD and copy over the file.