it is not necessary. the default windows 7 ide and ahci drivers support trim.
I found the Intel New Users' Guide very helpful. I'd sugest you read it. It was something I stumbled upon on the website but it provides useful guidance. I installed the Matrix Storage Manager as suggested by this Intel guide and it was useful as it lets you know the appropriate drivers are installed and whether NCQ is enabled on all your drives. I also found out the Superfetch service should be disabled so the guide is well worth reading.