PC hard drives can easily become full so this guide is here to show you some easy ways that will free up some space for you.
First you need to see how much room is left on the hard drive. You can do this by opening My Computer and right clicking on whatever hard drive you want and then click properties.This will bring up a window that shows a pie graph and the exact amount of space taken up in gigabytes. You can see an example in the attached image. Used space is in blue and free space is in pink. Above the pie chart, it says the exact amount of gigabytes for each of those. If it's under 50% full, you should be good. Anything above 75% used up is getting pretty full. If it's over 90%, you definitely need to do something about it. In the attached example, it's 78% full so this drive could use some cleaning up. First, click on the Disk Cleanup button shown in the attached image.
If you didn't choose to compress files, it should be done in a few minutes after you press ok. If you did choose the compression option, it may take hours to compress every old file it finds. It's definitely a worthwhile thing to do though if you need space badly. When the process is completed, take another look at the pie chart to see how the storage situation looks now.Speaking of compression, if you're at 95-99% full and you're totally desperate to free up a ton of room, there is an option to compress every single file on the entire hard drive. Right click on the drive in My Compute and click properties so it brings up the pie chart window. Under the chart, it has a checkbox that says "Compress drive to save disk space." Check it and click ok if you really want to do this. Only do it if it's absolutely necessary though because it will slow down your computer noticeably.
Another unbelievably enormous waste of disk space is the 12% that's allotted to system restore files. To turn this down, right click on My Computer. Then go to the System Restore tab and click Settings. The slider should be at 12% by default which is ridiculous. On a 120 gigabyte drive that means almost 14 gigabytes are being wasted on restore files! How often do you use system restore? And better yet, how often do you need to restore to a point from a year ago? Usually it's just the most recent restore point you need. And to keep around a month's worth just to be safe, it sure doesn't take 12% of the disk space. So turn the slider down to right above 2 gigabytes (2000 megabytes.) If you can afford the space, only turn it down to around 4 gigabytes. If you're desperate, you can turn it down to 0% but this may make System Restore not function properly if you ever need it.
Now your hard drive should be as open as possible. If you're somehow still out of room, you can buy a second hard drive and install it and move all your largest files to it. Any games and programs still need to be installed on the original drive though and can't be moved so if you don't have gigabytes of videos or other large files to dump off onto a second drive, you might still find yourself out of room on the original one. It is possible to buy a larger capacity hard drive and copy the entire smaller drive onto it plus expand what's called the "partition" so it fills up the entire space on the new drive and then you're all set with a larger "system drive" aka C drive. That process should only be done by professionals though because it's complicated and easy to screw up. And it's expensive so it's only worth doing as a last resort.