Yes.
Yes.
It depends on what aspects you are using. Elements on the cloud are ok, but the standard desktop applications of Microsoft Word, Microsoft Excel and Microsoft Outlook will not run if you download them onto a Windows XP machine.
It doesn't come with it, no. You have to buy Microsoft Office.
Yes, Microsoft Office is compatible with Windows 8. Microsoft Office works with virtually all new Windows versions, including Windows 8. Microsoft Office is a comprehensive suite of applications which includes Word, Excel, PowerPoint, OneNote, Outlook, Access, Publisher, and more. Office 2020, 2019, and 2016 versions are all compatible with Windows 8. You can download Office from the Microsoft website or you can purchase a product key from an authorized reseller such as Microprokey. You can buy a product key from Microprokey .com which guarantees a genuine Microsoft product key and the guarantee to work on your version of Windows. Once you receive the product key, simply follow the instructions provided by Microsoft to install and activate Office on your Windows 8 device.
They both share Microsoft office and all the tools in Microsoft office (word, excel, PowerPoint etc).
Yes, Office Basic has Word, Excel and Outlook
No. Windows XP is an operating system. Microsoft Excel is an application. It must be purchased separately. When you buy a computer you could ask to buy a version of Microsoft Office and have it installed on your computer, but it does not come automatically with your computer.
No. Excel is part of Microsoft Office. Windows 7 is the operating system and it does not include the Office applications, which must be bought separately if you want Office on your computer.
Yes even though Windows 7 is newer.
Using a Windows OS, Start->All Programs->Microsoft Office-> Powerpoint or Excel
Not even close. Microsoft Excel is a spreadsheet program. Windows XP is an operating system.
Programs->Microsoft Office->Microsoft Excel