Look at the device with "sudo file -s /dev/sdb" or the image file with "sudo file <imagefile>". If Windows says a filesystem is raw, it means it doesn't recognise the filesystem. I could just mean a Linux filesystem.
For the image file look at "fdisk -ul <imagefile>". Do you see a partition table? Did you image the entire drive or a partition?
If you imaged the entire drive, then you will need to use losetup to create a loop device for mounting the partition. For this you need the correct offset in the offset command. I suggested the -u option for fdisk to avoid rounding errors. The offset needs to be exact. I've usually seen the first partition start at block 63 on XP computers. I have a vista laptop and the first partition for this one starts at 2048. I don't know if that is typical for Vista or just the installation on a Toshiba laptop.
jschiwal@hpmedia:~> sudo /sbin/fdisk -lu /dev/sdb
Disk /dev/sdb: 250.0 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders, total 488397168 sectors
Units = sectors of 1 * 512 = 512 bytes
Disk identifier: 0xcab10bee
Device Boot Start End Blocks Id System
/dev/sdb1 * 63 174160664 87080301 7 HPFS/NTFS
/dev/sdb2 174160665 469917314 147878325 f W95 Ext'd (LBA)
/dev/sdb3 469929600 488391119 9230760 c W95 FAT32 (LBA)
Partition 3 does not end on cylinder boundary.
/dev/sdb5 174160728 469917314 147878293+ 83 Linux
For an image that looks like this, you could use
sudo /sbin/losetup -fs imagefile -o $((63*512))
Then examine the filesystem on the partition.
sudo file -s /dev/loop0
If the file command here or the fdisk -lu earlier indicated an ntfs filesystem, you can try to mount it.
sudo mkdir /mnt/test
sudo mount -t ntfs filename /mnt/test -o ro,loop,uid=<username>,fmask=111,dmask=000
If the image has a partition and you are unable to mount it, try to use photorec or another recovery program on the loop device.
If the mount command doesn't work, run photorec or another recovery program using the loop device.