2Mark Szkolnicki: Updating WinXP to win7 is possible, but note that win7 will require significantly more resources than winxp. The bare minimum for Win7 is 768 MB of RAM, but in case you disabled all "bells and whistles" like Aero and visual effects, and enable VT-x/AMD-V. Otherwize, it will run too slow. WinXP with 512 MB of RAM is an optimal variant even without HW virtualization. So, I'd not recommend to upgrade it to Win7.
> I can say that they do open (a hopeful start) and that I can access files from the host computer and others, through my peer network. I did try enabling the "shared clipboard" in VBOX through SETTINGS | GENERAL then the Advanced Tab and found that attempting to cut and paste between the host and the VM locked things up. Only tried "Bidirectional" at the moment (also has a Host to VM or VM to Host option), but, I expect, this being a developmental version that some code linking the OS and the VM clipboards is still needed.
Shared Folders should work with different guests (excluding OS/2 atm. I did not finished the shared folders IFS yet. But it currently allows navigating the file system and viewing the files. Though, it can crash the VM easily, so it is not stable yet, but partially working). So, host support for shared folders on OS/2 is working, but guest support is not yet.
Inversely, Shared clipboard host support is not yet finished, so it can easily hang your host system! So, beware. Support for shared folders on OS/2 guests should work, though.
2ivan: running two different VM's on top of OS/2 host is possible. At least, I ran two VM's, one with WinXP, another with Knoppix LiveCD (Linux). They are not prevent to run each other. Running a VBox inside VBox is not poossible, AFAIK, because VBox does not support nested virtualization. QEMU supports it. So, I was able to run VBox inside QEMU. It worked, but very slow. KolibriOS started for an hour, or so, in such VBox instance. (This is without HW virtualization/KVM. With KVM enabled, VBox runs relatively well inside QEMU).