If you have a second hard drive installed, you can copy the files there. Otherwise you are stuck with copying the files to a floppy.
Depending on the number and sizes of files, you may be able to copy them all with just one command.
At the C:> prompt, type "cd mydocumen"
The prompt should change to C:\MyDocumen>
Type "copy *.* a:" (If you have many documents, this will not work. This essentially tells DOS to copy everything in the folder "MyDocumen" to the A: drive, which may not have space for everything.)
If using wildcards (*) will not work you will have to copy each file individually or copy small groups of files. The syntax will be:
"copy file1.doc a:" or
"copy file1.doc + file2.doc + ... a:"
Hope this answers your question.