2 hard drives on my laptop

The question is do you have two hard drives in your laptop or a drive that has two partitions. Not all laptops hcan hold two hard drives. Provide the make and model number. If you have Windows, you can right-click My Computer, then left click properties, then left click hardware, left click the device manager control button, and left click hard drives and see if you have two hard drives. The alternative is to left-click the start button, left-click setting, left-click Control Panel, and left-click adminstrative tools, left-click computer management, left-click storage, and left-click disk management. The lower pane will show the number of disk drives you have removal and hard drives. If you have a 500 GB had drive it may have been partitioned into two 250GB partitions. The C: drive would be where your windows system folder is and your D: drive partition is where you can store data and install programs. You may have installed programs only on your C: drive partiton. The alternative may be you have two separate hard drives. The default installation partition is the C: drive partition for most programs. You can try to do a disk clean up to remove temporary files on you C: drive to help free up space. You can de-install programs you do not use to free up more disk space and you cna move the default location of the My Documents folder to the d: drive. You can de-install and re-install prgrams to you d: drive. Ideally you should have about twenty to thirty percent free space on you systems drive or partition.

You only have 1 hard drive in your laptop but it has been split into two partitions (like having two virtual drives).
If you store all your important data on the D:\ partition and for some reason need to reinstall windows your data will still be there (unless your hard drive has failed).

To free up space on your C:\ try moving the contents of your 'My Documents' folder to the D:\.
If you are running Vista or Win 7, go into your My Documents folder and do the following:

Right click on the folder you would like stored on the D:\.
Select the 'Location' tab.
Hit the 'Move' button, find your D:\, create a new folder with the same name and click OK.
When asked if you want to move all the files to the new location, click OK.
Repeat for all the folders you want to move.

Now the data will be stored on the D:\.
You can still access it through the start menu or the My Documents folder as usual.