how we can switch between windows and linux?
help me.

the question is vague and the title too, can you be more specific about the context you are talking in?

Several possible answers, depending on how we interpret the question:

1. Remove Windows and install Linux.
2. Install Linux on a separate computer and set up the two computers with a KVM switch.
3. In a dual-boot system, reboot and select the desired OS from the GRUB (or LILO) menu.
4. Set up a virtual machine in one OS, and install the other OS on the virtual machine.

I quite-frankly suggest that "it's not worth doing."

If you need to run programs that require the Windows environment, and programs that require the Linux environment ... "hey, hardware's cheap."

"So, what's expensive?" Easy. I'll tell you...

"Expensive" is de-stabilizing either one of those two environments, when you need to have both of them but ("whups...") you don't.

"Expensive" can also be "having to jump through any sort of 'hoops' at all" to get from one foot to the other, when you need (for whatever reason...) to be able to do a two-footed dance.

Let's face it:[list][*] A computer is "a means to an end." Therefore, 'the computer' matters not-at-all, and 'the end' is what we're after. If you have a business need to run Windows, and a business need to run Linux, then you "obviously" have a valid need to have two computers side-by-side on your desk.

(And what is the cost these days, really? $500 at Wal-Mart? ... )