No, if it is compatible with Windows 7 Professional it will be compatible with all versions of Windows 7.
doesn't work on your computer
Neither one is a particular computer (they are manufacturers, not model names), and neither has a product lineup solely compatible or incompatible with Windows 98. IBM made several workstations with PowerPC processors that obviously cannot run Windows 98, and newer Macs have Intel processors that can run Windows 98, though the hardware is not fully compatible.
Nope, the hardware is completely incompatible.
backwards-compatible
They are not always compatible. There are minimum hardware and software requirements. It is possible to use adapters and upgrade hardware in order to make them compatible.
All hardware used within a system must be compatible in order for the computer to operate properly
software will not work
No, both the disc's and the system's hardware and software are incompatible.
None. Windows is software, not hardware.
See the manual.
A computer or compatible with online access.
If you have moderate computer hardware knowledge and you are ok with small screws and screwdriver then you can do it yourself otherwise let a professional do it. Most of the hardware stores will do it for you if you purchase hardware from them.