Hence why he asked which one was it which was a valid question. Windows messenger is OS dependent while MSN messenger is net dependent. Windows messenger uses a different update engine than MSN. There should be no updates out for MSN 7 except maybe some patch but Windows messenger may be due one. So....if he downloaded MSN messenger and inadvertently signed in with Windows messenger, it will continue to ask for an update.
19" LCD|Asus A8N SLI Deluxe|AMD X2 3800+ @ 2.5GHz Cooled by Zalman CNPS9500|4 x GSkill 1Gb DDR 400|2.25 TB Total storage|eVGA 256mb 8600GT DDR3 @ 640/1600MHz cooled by ZalmanVF700|Ultra X-Finity 600W PSU w/ 135mm fan|1 x 120mm|4 x 80mm|Altec Lansing AC56|Windows7 x64 : Ultimate