(I asume you have no recent backup,
otherwise you would not have posted)
The reason not to use the disk is that
you cannot be sure that only windows is missing some parts to boot,
or your filesystem is realy hosed.
To do the least damage posible,
it is vitaly important not to try to mount or use
the partiton directly now that you know it is broken.
When your data is really important the best way (least risk of losing data)
is to get another harddrive where you can make a complete image of the broken partition using dd.
I know you can try to mount the ntfs partition using knoppix and other tools.
This is what I would recommend when windows would not boot because you installed a new mainboard
or other trivial changes.
In your situation it could be that the resizing of your partitions damaged
the filesystem structure on these partitions.
It may not be easy to recover from this failure.
There are tools to recover lost data,
some are better than others.
But first you need to copy your partition,
so you can than experiment with recovery.
If somethings breaks, at least you have a copy to start the recovery proces again.
I have recovered 20 gigs of Data ( university and work papers from my girlfriend who had win2000
crash and never recover again.... we recovered about 80 percent of the files)
So quick fix:
boot into knoppix (or equivalent) and try to mount the NTFS partition read only.
If this works, you just have to copy the files you need somewhere else,
reinstall, and copy the files back.
If this does not work,
(becaus NTFS cannot be mounted because it is in a broken state)
you may have more luck using NTFS recovery programms.
If this doesn't help ask again here.