Even with the large hard drives we have today, you can run out of space due to drives being partitioned in small segments.
Example, a 1 Terabyte drive may have 3 or more partitions and when you store lots of video or high res photos on such a smaller partition of say 400GB or so, you can often run out of space.
First you should have all essential data stored on an external drive, such as your photos and irreplaceable data.
I usually create a photo folder on my main computer and every once in a while I connect my smart phone and search the hard drive for new photos and then copy and paste them into folders on my hard drive. I may even have the folders show up when I synch my smartphone.
Anyway, as you start to use HD Video and HD images on smartphones and you start to put them onto your hard drive and you download large files and save them, you can max out 300GB to 500GB partitions easily.
You should back up all such data you never want to lose to an external hard drive such as a 1TB or 2TB ‘Passport’.
Once you do have your backup done you can try to free up space without deleting large files with the built in File Compression that comes with windows.
In my example I still use Windows 7, so the little icon on the bottom bar of the OS has an icon with a file folder.
Windows 7 File Compression Steps
1. Click on file folder icon bottom of screen
2. Click on the drive you want to compress
3. Right click the drive you are on in the left hand navigation pane
4. Click the PROPERTIES task
5. Click the box to compress the drive you are on
6. Select APPLY
It may take 12 hours or more to compress all your files. If your processor isn’t that fast it could take over a day.
However you should gain between 10 to 20% space on your heavily used HD without deleting a file.
Once that space is used you will either need to upgrade to a newer computer or get a larger hard drive and you may want to partition so you can have the largest sized partition your OS allows.