Where is all my memory?

[Rex]

I currenty have a 250Gb hard drive.  When I look at the overall usage in the C drive it says i've used 130Gb.  However, if I search each folder shown as being in the C drive the amount comes to 80 Gb, thus i'm 50 Gb missing....where is it?!!!

[soybean]

You should edit your post to change the title to Where is all my drive space?  Memory, or RAM (Random Access Memory) is temporary storage that loses all data when the power is turned off.  Space on your hard drive is what you are asking about.

Is your Recycle Bin empty?  How much space is your system using for virtual memory, i.e. paging file?  How many Windows restore points are being stored by your system?  Do you use hibernation in lieu of shutdown? 

I believe all these are things that can consume some drive space, yet be somewhat invisible to you.  I can't say that they would account for 50GB, so I'm not sure what else might be a factor here.  Let's see what other replies say.