Oracle 10g is not supported under Windows 7. It may be possible to get it installed, but do you really want to trust something like a database system on something it's not certified for?
If this is a serious business application then you probably should go for Oracle 11.
If you really must run 10 rather than 11 I'd install XP or Vista in a VM and run it there.
I don't know how well Oracle can be uninstalled when you are done and, for that reason, I suggest you install it in a Linux VM using VMWare. It will require more RAM, but will probably save you a lot of trouble.