Are you talking about Genesys CTI software, or some other Genesys?
If it is the CTI software, the client apps Config Manager, WFM Config Utility, OCM, CC-Pulse etc. should run fine (you might need compatibility mode). NOTE - Windows 7 may not be supported, so if you are working in a production system, check the supported OS documentation on the support site.
Server apps DB-Server, Config Server etc. did not run under XP, so are unlikely to work under Windows 7. For these apps you need a server OS (Server 2003 or 2008). As already mentioned in this thread, VMware is good for this.
With a bit of trial and error you could probably get the clients on Windows 7 talking to the server apps on a VMware image running on the same physical machine, although it might be easier to build everything on a virtual image.
I guess it comes down to what you are trying to achieve, if you just want the clients to access an existing platform or if you are building a model/playpen for practice.
Steve