disk management

I installed Windows 7 Ultimate on a new hard drive (Seagate 1 TB) from system image. My old hard drive was a 500 GB but was partitioned into C: 304.82 and D: 148.33. When I look in disk management, I see 465.76 GB and 6 MB of unallocated space. How do I make it all one drive again or should I keep partitions. The drive was partitioned when I bought the PC from an individual, but that drive has failed now. It is now installed on the new hard drive. Please help.
I hope I didn't confuse you with my post.

Thank you
Fay

The rest of your space probably stayed unallocated in Disk Management, post a screenshot of it as described in Disk Management - Post a Screen Capture Image

You should be able to extend to the free space to the right of current partition, still post that screenshot so we can guide you accurately.

I hope I did this right.

Select D: in Disk Management and right click on it.
Select Extend from the list and next all the way.

Extend is greyed out

Try with Partition Wizard free.

I downloaded Mini Tool Partition Wizard, but I'm not sure how to use it. What should I do? I want to make C drive all one drive. I just don't want to make a mistake.

Oh sorry, I mis-read your first post. To make C one big single partition: It is easy since your D is empty. You can simply delete D with Disk Management so everything on the right of C become one big unallocated space. Then right click C and extend it.

However, if you ask me, in short, reduce C to less than 120GB (Windows + programs), make the rest one big D (games + personal data) and then use imaging software (macrium free) to make occasional images of C, and a file sync program (like FreeFileSync) to keep a copy of your games and personal data. Hope this makes sense to you. This one requires a bit of work from you, if you want this ask again so we can provide a detailed action.

I would prefer a step by step tutorial please. :) I don't want to mess anything up.
If I reduce C and make D bigger, do I point everything to D when installing? I still have a lot of files on C too.

Your programs and Windows files shouldn't take too much. You will only point your Games to D, regular programs will stay on C.

Before we start please make an image of C to your external with Macrium free - Imaging with free Macrium, even though it shouldn't cause any problems, there is always the possibility. Don't forget to create the bootable media of Macrium as well.