Yes, you can reinstall windows xp media edition whenever you want, by just inserting an windows xp media edition CD into your computer. I don't know if you can roll it back though.
18 months
To set up a default means the settings of such device or computer is the original from when it was bought. All other alterations or changes that you made will all be erased.
Default means original whatever conifguration it changes to its original settings.
There is no such thing as a 'default network'. Perhaps you meant 'default gateway'?
Yes. You can add extra worksheets into a workbook. The amount is limited by the memory of your computer. By default, there are always 3 worksheets in a new workbook. It is possible to change the default.
a default gateway is the default access point a computer or device uses to connect to the internet.
In computer Language the meaning of "default" would mean standard settings, but the actual word has a different meaning when used in a general sentence, for example : He won that game by default. When you use default in that sentence it states that he won by fault, either penalty or whatever, but that is what default actually means, yet in the computer language it stands for standard settings basically.
Default route
The default identity letter for the internal drive of a computer - is C.
He wasn't paid that month, so he defaulted on his debt.
Default settings are used in the computer for the simple purpose of easy personalizing. Default settings are meant to please in the minimum of appearance if not the maximum. Otherwise they'd have to have one person set up each and ever computer made according to how he or she likes it.
default setting is the original setting, until changes are made