Solved Windows doesn't recognize full capacity of hard drive

I recently bought a new computer with pre-installed Windows 7 Home Premium. The HDD inside is supposed to be 1TB but Windows only shows 55gb available, of which over half is already in use. I checked from BIOS and it recognizes the drive as 1000gb. I've searched all kinds of forums and DIY -tips but haven't been able to find anything useful. I'd call customer support but it's a holiday today in my country and all the places are closed, so I wondered if anyone of you guys could help. If not I'll call tomorrow.

Thanks in advance

Open start menu and type in disk management, hit ok.

Please post a screenshot of it.
http://www.sevenforums.com/tutorials/9733-screenshots-files-upload-post-seven-forums.html?ltr=S

I hope it's not a problem that it's in Finnish
But as soon as I opened the management I understood what you meant. I saw the unused 850+ gb part of the disk and tried to create a new partition but I got an error that (roughly translated): The disk(s) don't have enough space to complete the action. First I tried with the whole 867,49gb you see in the picture and then with only 500gb with same results.

Sorry for the double post, but I solved it. I changed the HDD into a dynamic drive so it let me extend the unused part to the existing, used part. Thanks speedgamer01 for that disk management tip. it really helped me a lot

Here is a free partition wizzard
MiniTool Partition Wizard Home Edition - Reviews and free MiniTool Partition Wizard Home Edition downloads at CNET Download.com

I suggest you to delete the empty partitions but not the System (C) in Disk Management

So now the disk is empty expect C: in the middle

Now open the partition wizzard (i don't remember how to) but you can easily move the partition to the beginning of the drive and then you can resize it..
Here is a video that might help

Thanks for going through that trouble, but I managed to solve it with Windows' own tools as I posted a few minutes ago. Thanks anyway, you helped a lot