However, while 32-bit drivers are not directly supported in 64-bit Windows 7, 64-bit Windows 7 users can install 32-bit drivers in Windows XP Mode and use USB-based printers and other USB-based ...

Knowing if your copy of Windows is 32-bit or 64-bit becomes very important when installing device drivers for your hardware and choosing between certain kinds of software.

This article will teach you how to install the Microsoft Access 64-bit ODBC driver, as well as how to fix problems with ODBC when using Java to access a Microsoft Access database in the 64-bit version ...

64-bit because you eventually have to start installing 64-bit drivers on the 32-bit server to either support 64-bit clients or to allow you to migrate to a 64-server in the future.

The same product key works for both 32-bit and 64-bit. Bitness doesn't matter, so your question should be equivalent to: Is it okay to install Windows 7 and then reinstall it later?