You can’t that is the formatted capacity of your hard drive. You have to have some overhead for the format also manufactures measure hard disk size is in decimal were as Windows reports hard disk size as 1024 bytes to a kilo byte and 1024 kilo bytes to a mega byte and 1024 mega bytes to a giga byte or 2^30 bytes.
That's not formatting loss. Your drive is (as far as windows is concerned) 74GB. That's because according to drive manufacturers (and pretty much everyone except operating systems), 1 GB = 1 billion bytes. However, to the operating system, 1GB = 2^30 bytes. Because of this, drives will always appear smaller in windows than they are advertised, but you do actually still have all of the space.
Just to be nit picky, the space on your drive is not called "memory." Memory is commonly speaking about the RAM (Random Access Memory) you have in your system. Memory is volatile, meaning when you power the sytem down, anything stored in "memory" disappears, you lose it. The drive it's self is non-volatile, meaning whatever is stored on it stays there until is physically removed or written over. It does not go away when you power down the system.
The correct term for talking about hard drive space is simply "storage" or "capacity".