Need to allocate more space to C drive

My girlfriend came to me saying she was trying to do something on her windows 7 computer and it said she had no space to complete or something. I have never owned a windows computer so I am a little rusty on the subject. Looking at her computer she has 58 GB on her C drive and a little under 400 GB on her D drive. She had ~175 GB free on her D drive and almost none on her C drive. Is there any way to take space from the D drive and add it to the C drive?

Also, I think its odd that her C:/users folder is only 25 GB. My assumption is most everything she installs and adds to her computer will go into the users folder. If she has a 500 GB HDD, why would 60%+ of the HDD be in use? is windows 7 just that big?

Have a look at the libraries. Documents, pictures, music,video. All of that can be moved to D. Then just add the new folders to the library by right clicking documents/properties/include a folder. Do that for the others.

First check to see how much is in the libraries.

Welcome to Windows Seven Forums.

You really need to find out how your girlfriend is installing her applications before you go any further.

Once you've done that, run disk cleanup and uninstalled anything she doesn't need, such as unused programs and old backups, you can consider resizing the hard drive partitions.

Many of us use Partition Wizard as it is far more versatile than the Windows disk management utility.

Partition Wizard : Use the Bootable CD

Thank you all for your replies. Why would they make the D drive so big and the C drive so small? looks like there is nothing in the D drive really. If I re-partitioned the drives, would that delete some stuff? would I need to back up everything before doing that? Everything she downloads is to the C drive so I dont want to just switch everything over.

If you want to keep things really simple you could just delete the D drive and extend the C drive to take up the resulting unallocated space.

Obviously, you'll need to backup anything of importance first, but the payoff is that with just one partition on the drive there'll be no question of where applications are installed to or downloads kept.

The C drive would have been kept smaller because the minimum requirement for Windows 7 is 20GB although I think 100GB is a more realistic size depending on how many programs are installed.

Deleting a partition will result in losing anything you haven't backed up, whereas repartitioning may or may not result in loss of data depending how it is carried out.

Your options are to move the User folders to D drive to keep your data separate so the Win7 OS/Programs image is smaller and easier to store externally. Then if Win7 ever becomes irreparable you simply reimage it to C while your files are current, safe and waiting in their separate partition.
User Folders - Change Default Location
Backup Complete Computer - Create an Image Backup

Another option is to delete D after moving its files to C, then extend C into its space:
Partition or Volume - Delete
Partition or Volume - Extend

And another option is to use free Partition Wizard bootable CD to resize D from the left side to make more space for C, then Resize C to the right to take up that space.