ID:183510
 
It's probably just your cache. That baby can get big.
Actually, I just read something that had to do with this(non BYOND related). The way it calculates size is by reading the BYOND folder size. As already stated, the BYOND cache can get pretty big. It's safe to go in there and clean that out.
In response to Danial.Beta
Perhaps he was talking about the TWO Byond entries?
That seems odd too.
In response to Flame Sage
My Vista install of BYOND has two entries. It hasn't seemed to hurt so far.