how do i format a SD card so that i can use the whole Capacity ?

[Legion 739]

I bought a 8GB sandisk MicroSD which i formatted using my cell phone.
After formatting the total memory size changed to 4GB.
And now even after formatting with PC i cannot use the whole 8 gb.
Please help me to solve the issue.
Any help would be appreciated..

 

[Dr Who]

XP might only recognize up to 4 gigs. And your cell phone might only recognize up to 4 gigs.