External hard drive format

I just purchased a 500GB Verbatim Acclaim external hard drive I noticed that it came with some software on it, dcreasing its size down to 465GB, I would like to format the drive to have 500GB of space, would this be safe?

Yes. You are worrying about a nonexist problem.

For Hard drive manufactures, 1GB = 1,000,000,000 bytes
For Microsoft Windows, 1GB = 1,073,741,824 bytes

500GB drive = 500,000,000,000 bytes according to the hard drive manufacturer.

Windows reports this drive with a capacity of
500,000,000,000 bytes / 1,073,741,824 bytes per GB = 465.66 GB

This means that the 500GB will show up as 465GB in Windows.
500GB (drive manufacturer) == 465GB (Windows)

I use external hard drives to store all of my photos and for my backups. External hard drives are great, but they must be formatted properly for before you start filling them up with important information. Here’s a link to an article that I recently wrote on my storage and backup system. Most photographers will want to format their new external hard drives using their operating system’s optimal style. NTFS is the standard for Windows users and OS X Extended is the standard for Mac folks. Most photographers using Macs will not get any extra benefit from the “case sensitive” option.

Like they said, you hard drive size is correct. Hard drive manufacturers use the decimal system while computers use binary. It's a marketing thing.