Only 300gb of hdd space is shown instead of 500gb.

I BOUGHT A NEW CPU CONSISTING OF 500GB OF HARDDISK.WHILE PARTITIONING THE DRIVES I FISTLY MADE A DRIVE TO AROUND 97.7gb SO I WANTED IT BE ROUND TO 100GB,BUT NO CHANGES WAS EFFECTIVE AND INSTEAD THAT 100GB CHANGED INTO UNALLOCATED SPACE AND THERE WAS NO OPTIONS TO REALLOCATE.I TRIED PARTITON MAGIC SOFTWRE TO RECOVER THAT 100GB OF SPACE AND I DONT KNOW HOW TO USE IT UNKNOWINGLY I DID SOMETHING AND AFTER THAT ONLY C DRIVE WAS THERE IN MY COMPUTER NO OTHER DRIVES ARE DISPLAYED.
SO I WANTED TO FORMAT MY SYSTEM AND I STARTED FORMATTING I WAS ASKED TO PARTITION ONLY 300GB OF SPACE.EVEN IN BIOS SETUP ONLY 300GB OF SPACE WAS SHOWN.WHEN I PURCHASED IT WAS CORRECTLY SHOWING 500GB OF HDD.

PLEASE ANYONE HELP ME OUT OF THIS PROBLEM.

PLEASE TELL ME THE SOLUTION FOR THIS PROBLEM.

THANK YOU IN ADVANCE

Go into Disk Management and post a screen shot of what it shows about your disks and partitions.

THOSE ARE SCREENSHOTS OF DISK MANGAMENT and VOLUMES

While you were "partitioning" you must have clicked shrink partition, and it shaved 100gigs of your c drive.... if what you are saying is you want your 100 gb back to your other space, in the disk managemnt screen you have showing, you should be able to right click the 100gb (D) one, than click delete volume, than you should be able to right click on (C) and click extend volume. it will ask how much you want to extend it, and just do all available. But it looks like you have 50 gigs of stuff on your D drive, im not sure what this is but, whatever it is you hsould put it all on an external hard drive to get it back to your C drive.

@bmcdevitt
are u sure that this would do?because i am totally amateur in this field.

Ya i tried and it worked. thank you very very much.

no problem, glad it worked out for you.