Windows 7 folder size discrepency

[paradive]

i do a backup of my stuff manually each month via an ext. HD.

right now, i was backing up my AppData folder (so much is in there!).

being anal, i compared the size of my laptop's internal HD compared to the ext drive when it was done.

results:
internal: 5+ BG
ext. 2+ GB

so i compared the size of each subfolder to see if they match up and, yeah.

conclusion: windows is hiding something from me.
but what?

p.s. yes, i have "show hidden files and folders" ticked.

 

[whs]

How did you back that up - maybe the backup is compressed. And why on earth do you backup Appdata - or this part if a whole system image.

 

[paradive]

How did you back that up - maybe the backup is compressed. And why on earth do you backup Appdata - or this part if a whole system image.

nay on both points.

i manually copy over certain folders.
and AppData is important to me cuz that's where saved games are, as well as browser and email info.