Slipstreaming XP SP2 in XP SP1 help

[Guest]

After Slipstreaming SP2 in XP Pro SP1, I noticed there were 3 files :

WIN51 (1KB - File)
WIN51IP (1KB - File)
WIN51ip.SP1 (1KB - SP1 File)


Do I still need these 3 files? or do I just need the WIN51ip.SP2? Thanks for your help