Note that if you are on V5R4 of the OS, Clent Access will not be supported for Windows 7. Here is text from the IBM site I found.
IBM i Access for Windows Support for Windows 7
This information provides insight into IBM’s current plans and directions and is subject to change or withdrawal without notice.
The V6R1 IBM i Access for Windows client will begin supporting Windows 7 as part of the next V6R1 IBM i Access for Windows service pack, scheduled for release on December 1, 2009.
There are no plans to support the V5R4 IBM i Access for Windows client on Windows 7.