Hi to everybody!
I have a computer with the following features:

CPU: PENTIUM 3 500 MHZs
MOTHERBOARD: MSI - 6119
RAM: 128 MB
HARD DISK: WESTERN DIGITAL 7.6 GBs
VIDEO CARD: S3 Trio 3D 2X AGPs 4 MB

I decided to divide my hard disk in FAT16 partitions in this way:

C: 1 GB DOS 7.10 - WFW 3.11;
D: 2 GBs for data;
E: 180 MB for the swap file.

and I devoted the rest to Linux.

From months I have performed Windows 3.1 with DOS 6.22 but I wanted to update this version of DOS to overcome the limit of 64 MB of RAM.
So I installed MS-DOS 7.10 (the DOS version used by Windows 9x) and together Windows 3.11 for Workgroups after having updated the system files of DOS 7 (exactly IO.SYS) with OSR2FIX patch. Now Windows 3.1 works on MS-DOS 7.10 without problems and the system exactly sees 128 MB of RAM (more than 64 MB).

Before updating I attentively followed the instructions contained in the document W3XSTART.DOC where it was written that some programs (for instance Microsoft Word 6.0) display the following message in start:

YOU MUST EXIT WINDOWS AND LOAD SHARE.EXE IN ORDER TO RUN...

because the file-sharing support doesn't exist in MS-DOS 7.10 real mode and this prevents the driver VSHARE.386 of Windows 3.11 to perform its own function.
This wasn't happened to me. I inserted in the file CONFIG.SYS the voice DEVICE=C:\WIN311\IFSHLP.SYS, I typed the command LOCK E: to allow the access to the disk and I set the permanent swap file on partition E: and I finally enabled 32 Bit File access. I installed OFFICE 4.3 for Windows 3.1 and I performed Microsoft Word 6.0 and all the other programs such as ACCESS 2.0, EXCEL 5, PUBLISHER 2.0, etc... without problems and therefore despite to how much writing in the document the driver of Windows 3.11 VSHARE.386 HAS REGULARLY WORKED! .
However I tried to disable VSHARE.386 in the section [386enh] of the file SYSTEM.INI inserting the voice ";device=vshare.386" and I installed SHARE.EXE of DOS 6.22 but Word 6.0 and Excel stopped working after having displayed the message: YOU MUST EXIT WINDOWS AND LOAD SHARE.EXE
I think that the problem of the lack of the file-sharing support (provided by VSHARE.386 of Windows 3.1) subsists in MS-DOS 7.10 only on the hard disks greater than 7.8 gbs, with more than 1024 cylinders and on FAT32 partitions where it is not possible to set a permanent swap file as it is written in the file W3XSTART.DOC of the patch. My hard disk exactly has 973 cylinders, it has therefore an inferior capacity to 7.8 gbs and everything regularly works.
Thanks for reading this message!

Interesting. Anyway, there is a Share.exe that works in MS-DOS 7.10 and it is included in Wengier MS-DOS 7.10, and also once I found a "fake" SHARE.EXE that does nothing, just fake programs to tell sharing is enabled.

I have downloaded that famous "share.exe" mentioned by alexanrs that solves the problem (I think it originally comes from ROM-DOS 7.10). Used it and found useful as regards MS Word 6.0, which now runs smoothly under MS DOS 7.10 and Win 3.1. Still having problems with MS Access 2.0, however, which refuses even to load, stating something about a problem in "system.mda" file. I'll try inserting the line DEVICE=C:\WIN311\IFSHLP.SYS in CONFIG.SYS, as suggested by Tonio, and report again...