It appears you are confusing hard drive capacity with RAM memory. A average PC might have an 80GB HD, and 128 or 256 MB of RAM (memory).
It is the latter, that is the problem. To run samples, you need a minimum of 512MB of RAM . You could get by with 256 with sounfonts that are not too large. Memory is cheap these days. Get as much as your machine will hold if you want to get into sampled instruments eg.
Your hard drive is nearing capacity, but won't interfere with you loading soundfonts.
Go into control panel\system and see how much memory of RAM you have. I can't run SGM180 on my PC with 352MB RAM. I have to go to my Receptor with more RAM.
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