if you dont have very much on ur hd will ur comp be faster than if it did have alot of space used up? this is something I allways believed but never based it on anything than just assumption.
I don't think it matters that much. But if ur hdd is really full (like under 100mb left) then it probably will make some difference.
But this is just a gues, not a fact.
if you only have one drive platter, and you have a small amount of space left, it will definatly make it slower. it takes longer for the read head to search through your other information to find the certain part on the platter you requested
This is where partitions come in. The best thing, for an advanced user, is to set up one for Windows XP, say, 2-3GB, then, one for games, then one for media. That will be faster, compared to whacking it all on one drive.
I personally use 30GB for Windows XP + Programs, then 50GB for media.