Stacey has a Dell Inspiron running Windows 7. Can she upgrade it to Windows 10? Leo says yes, and she can do it for free through July 29th. She should wait until she gets the invitation, that means her hardware is compatible. If she missed it, she can download and install the Windows 10 ISO file. Then she can enter in the Windows 7 serial number when she installs it.
Leo recommends installing fresh on a formatted hard drive. Going from 32 bit to 64 bit is a bit tricky, though. Microsoft has a document on how to do this at answers.microsoft.com.