disk space problem

For some reason, my HDD’s space decreased from 43.6GB to 39.0 GB without anything installed. Any suggestions to how i can restore this to normal?
Answer #1
Start from the temp folder…Probably full of junk…Recycle Bin…Empty it…Check out how big is your pagefile
Answer #2
install ccleaner (will do what suggests and slightly more)
http://www.ccleaner.com/download
Answer #3
done. Increased to 50 something GB.
Answer #4
add [Solved] to ur topic
Answer #5
how to?