Hard drive size in USB incorrectly shown

[mnabpk]

Hello,I have 30 gb samsung hard drive which i formatted By Fat32. when i connected it to usb port via USB 2.0 to IDE cable my Windows 7 shows that drive should be reformatted. When i gave format command, the size shown for formatting is 20GB. Can you guide me about this problem

 

[house70]

Why do you use Fat32? That has a different block size and that would cause the difference. Has the drive been partitioned before? Even by the manufacturer?
If it was, there is a way to get all the space back on it, but will require a low-level formatting or a zeroing of the drive, to restore it in factory-clean state. If need details about that, let me know.

 

[mnabpk]

i had formatted it by installing it in CPU. i formatted it in fat32 because i wanted to use it externally for data storage vis USB to IDE cable pack. It showed correct size when formatted, but when i connected it externally the size shown was 20GB and it required reformatting (although it had been formatted already). Actually i had practiced this previously when i used windows xp and it went fine. but with windows 7 it shows wrong size... to worry me

 

[house70]

you can use NTFS as an external drive, as well. There is no need for it to be Fat32. Actually, NTFS allows you to use it for files larger than 4Gb (if I remember correctly the limit). Fat32 does not allow that.
I would try reformatting as NTFS, but again, after doing a low-level format (you can use Killdisk to achieve that). If you do the low-level first, it will show the whole drive capacity.
If you want to keep the Fat32, you can choose that after the low-level formatting, as well.