help rescue my old files

I have some files in the disk C:(system) of my old PC with Windows98SE. When I turn on the computer, I get the message:

Error,loading gdi.exe, you must reinstall Windows.

and then the computer shuts down automatically.

How do I do to save my files in the computer. I used Safe Mode to try to transfer the files to my external HD or flash drive, but failed,because in this safe mode, only do the C: AND A: disk display.

Please help me to solve the problem.

Thanks a lot!