Help...please...my VBOX Windows 7 does not start anymore??

[Kinjapan]

Dear all,
it is unfortunate - as stuff like this always seems to happen when you really need to get stuff done.... I did fiddle around with disk size in VBox as I was afraid that it might have become too small and followed some instructions in Terminal, what I did as well was to compress the hard disk with settings in Windows 7....now, can't restart Windows 7 any more on my Virtual Machine. I am running Mac OS X Mavericks and all worked perfectly...
I truly hope, that by eg. deleting and reinstalling I can have access to my Virtual Machine again? Any friendly people out there who might be patient enough to help me? THANKS in advance!!!

here is the fault code when trying to launch Windows 7 on my VM:

It first says: Restoring Virtual Machine (background is somehow grayish but shows Windows 7 surface

and then windows closes and message appears in Oracle VM Virtual Box Manager:
'can 't open new session for virtual machine Windows 7'
and

pci#0: Device in slot 0x58 has been removed! vendor=0x8086
device=0x265c (ver=3 pass=final)
(VERR_SSM_LOAD_CONFIG_MISMATCH).

when I click on "Details" it appears:

Fehlercode:
NS_ERROR_FAILURE (0x80004005)
Komponente:
Console
Interface:
IConsole {8ab7c520-2442-4b66-8d74-4ff1e195d2b6}

any help would be really appreciated, guys, regards from Australia, Kinjapan

[Perryg]

VERR_SSM_LOAD_CONFIG_MISMATCH

Did you do all of this while the guest was in saved state? (not shut all the way down)

[Kinjapan]

Perryg, I am not sure, I did restart the VM, then shut down, then try to increase the size in Terminal, .... might be that the VM was at times still up and running....?

[mpack]

If you have a saved state associated with this guest then try discarding it (right click in UI, "Discard saved state").