The cache defaults to drive C, because IE defaults to drive C, which is the trace of surfing the Internet.

No matter which disk has too many, it must be cleaned up.

1TB It doesn't matter how big the C drive is.

Generally speaking, XP system only needs 20G-30G, but since yours is big.

Hard disk, I think it is more appropriate to leave 100G, even if XP system is replaced by VISTA and WIN7, it will be easy.