virtualbox.org

I resized my virtual HDD using the command:

"C:\Program Files\Oracle\VirtualBox\VBoxManage.exe" modifyhd "C:\Users\XXX\VirtualBox VMs\Ubuntu\Ubuntu.vdi" --resize 250000

to make my HDD 250 GB. It appeared to work, except it shows that the virtual size is what I wanted (244.14 GB) but the actual size is still 90 GB like it was before I resized it.

Now when I start my VBox it says that One or more virtual hard disks, CD/DVD or floppy media are not currently accessible blah blah blah..

How can I fix this?

Before I got this error, I got the error "The system is running in low graphics mode" and that would hang.
I have not been able to reproduce this error since I have gotten the one I mentioned previously.

I am using the VBox to run Ubuntu on a Windows 7 host.
I have the latest VBox update, everything worked fine before I resized the HDD.

Help please?
I don't want to delete the VM and reinstall it, as I have things on the HDD that I need.

I cannot access my ubuntu OS now, so how would I run this fix you've suggested?
Also, the partition doesn't exist on my windows machine. Atleast it doesn't recognize it as a partition. The file that I need to modify is the Ubuntu.vdi