Hard drive space decreasing and showing less space available

[GPedis]

Hey guys,
I'm having a big problem with my hard drive space. First of all it keeps decreasing for no apparent reason when i am connected to the internet even though i'm not downloading anything. And i'm not talking about mb but GB!! My first guess was a vius so i ran my antivirus (avast) and removed some issues, but the trouble continues... I installed the WinDirStas as i saw in other posts to find if i missed something. And to my surprise i discovered that my HD is occupied by ~80GB of unaccessible files! I'm not sure i am saying that correctly so see for yourselves...

 

[DMHolt57]

I think you should read as 8 point 8... but you do need more overhead for Windows. Look at your pagefile settings in System and maybe have a look at what Windows Indexing settings are...

 

[GPedis]

It seems i should've seen this before posting.
Sorry about that i should've looked that up in advance. I don't know if that fixed the first problem as well though...

@DMHolt57 Sorry man but i understood none of the above.