I have a question for really experts.
I boot directly from vhd (windows 7 ultimate) without any other system installed. I divided my hdd 320 gb into two partitions/volumes 100 gb and 197 gb

(remaining place 23 gb may be used by fat). the vhd was set to (i do not remember in detail) – i think – to 97 gb. after some updates for windows the blue

screen of death appeared with “VHD you must have enough capacity on the underlying disk to fully expand the VHD”. so i did a look on the facts. booting with

dos showed me the the vhd is about 18 gb large. i changed the two volume sizes with acronis disk director suite to 150 gb and 147 gb. after that the pc

started up normal without blue creen of death. then i opened the windows explorer and look at the free and occupied space of the started vhd and the two

volumes. and here i found something very interesting:

started vhd: free 78,4 gb /total 95,7 gb which compares to 100.000.000 mb which had to be set in diskpart
volume 1: free 47,5 gb / total 148 gb
volume 2: free 142 gb / total 149 gb

now my question: under dos the vhd only occuppy 18 gb which expand after starting from it to the set 95,7 gb,. that is ok. but on volume 1, where the vhd

lies, the started vhd uses 100,5 gb (148-47,5=100,5)!!! and 100,5 gb is larger than my set 100 gb for volume 1. that should be the reason for the blue

screen. but what i not understand is:

why expand the vhd over 100 gb when there is only 18 gb occupied under dos. i expected that the vhd file expands when the 95,7 gb runs full, not that it

expands when nearly 80 gb are free in the vhd. can someone explain this because this is not the purpose of a vhd?

another questions is: where are the 4,8 gb, difference between 100,5 gb (if vhd is startet, occupied on volume 1) and the shown size of 95,7 gb of vhd in

windows explorer? or i misunderstood something or mismatch some figures.

if someone can explain me this facts this may help a lot of other people to set the size of the vhd more sensible.

with kind regards

Rainer