I have recently found a surprising thing. When a TDL is used for a client, it was working fine in a system with Windows XP. But when the same TDL is used in another system with Windows 7, the RAM being consumed was unusually high. The same thing happened even when we tried it on a system with Windows 2008. Does anybody have any idea, on how it happens? Any possible solution? While on XP, it was using RAM around 400 MB and on other OS it is crossing 2 GB.