Does restore using .VHD file affect target partition or all partitions

Hello friends,

I did a backup of only System Partition (C:\) using Acronis True Image software. The backup is
a .VHD file. From then till this date, the other partitions have been loaded with data which i am not
able to backup to an external HDD since it's already full. My question is if i restore from this image,
then will it erase only the partition that i had backed up (C:\) or other partitions as well ?
Indeed, thats my fear.
Please help.

Regards

I've used Acronis True Image for quite a while, and I have always had no trouble with ATI "meddling" with a partition that was not being restored. However, if the partition(s) have been resized -- don't know what ATI does in that case.