Hardware: Acer Aspire 4720Z Laptop (Pentium Dual Core, 2GB RAM, 100GB Disk).
Platform: DOS 6.22, in Microsoft Virtual PC 2007, on Windows Vista Home Premium SP2.
Application: INFORMIX-SQL 4.10.DD6 (DOS).
Settings: CONFIG.SYS (DEVICE=C:\DOS\HIMEM.SYS /TESTMEM:OFF /Q);
                AUTOEXEC.BAT (SET DOS16M=3)

Description:
1. After DOS 6.22 boot, 614K real mem. and 65MB extended mem. available.
2. All DOS and INFORMIX environment variables are properly set.
3. I have an app. written with protected-mode  INFORMIX-SQL 2.10.06E working,
    (see video-demo at www.frankcomputer.com).
4. I installed INFORMIX-SQL 4.10.DD6 (Protected Mode DOS).
5. The database engine (PSTARTSQL.EXE) size is 535K.
6. When I execute PSTARTSQL.EXE, I get "DOS/16M error [6] INSUFFICIENT memory to 
    load program". This engine is supposed to load into extended memory, not in real.
7. I tried all DOS16M switch settings according to Rational Systems documentation,
    removing all TSR's, including FSHARE.EXE, which allows me to share
    Windows Vista drives, devices and folders with my DOS Virtual Machine,
    (Examples:  DOS Drive F: = Windows Vista Drive F: (USB Flash Drive);
                       DOS Drive C: = W.V. Drive C:,
                       DOS Drive T: = W.V. C:\Users\Root\Transfer,
                       DOS Drive L: = W.V. Parallel Port (LPT1:),
                       DOS Drive U: = W.V. USB001,
                       DOS Drive X: = W.V. Mapped Network Drive X: to Linux Server. 

      LAST DRIVE=Z: