I start my virtual server from yesterday and move my sites to it.
There is one problem which I can’t understand it.
Task manager shows the Ram in use is 7.5 GB, it is very high for server status while in last server this web sites uses 3 GB ram only.
I check all process on server and calculate sum of their memory usage : it was not equals to RAM usage report , sum of process memory usage was about 2 GB.
If I end all process still there is many RAM in use.
If I restart server for awhile ( 2 hours ) every things are ok and then usages increase .
Is every things ok On server? Is this a software problem? Can you please tell me how can I find the solution?

Thanks
Mehdi 

using this thread [Memory usage on Server 2008 keeps increasing without showing what is using the RAM](https://serverfault.com/questions/154702/memory-usage-on-server-2008-keeps-increasing-without-showing-what-is-using-the-ra) 
I find that the mysql database server use my RAM