Hello,
a couple of days ago i got a new dell laptop with vista basic pre installed - the only new program i ave installed in firefox web browser, have downloaded probibly 1GB of media files but deleted then all.
The laptop suposibly has a 120GB HDD but in 'computer' OS C: i only have 90GB of 101GB above that is 'Recovey' D: with 7GB free of 10GB - so where is the other 20GB of HDD?

thanks

PS: i have cleared restore points.

So you have a ~101GB primary partition and a 10GB recovery partition. That's 111GB.

A 120GB HD is not 120GiB. in HD-manufacturer-speak, that's more like 120 000 000 000 bytes, or ~111 GiB.

Nothing's missing.

This is the most frequently asked question. Really, people should search before asking such questions.

120GB = 120 x 1000 x 1000 x 1000 bytes for the manufacturer (so 120000000000 bytes)
So system see 120000000000 bytes and transform to Gb but with the classic 1024 unit ..
so the result is 120000000000 / 1024 / 1024 /1024 = 111,75 Gb

and yes it's the really most frequently asked question ^^

so a 120GB HDD is only 111GB

i did actually look back several pages to see if any one had the same problem all i could find was:
http://www.msfn.org/board/index.php?showtopic=94191

RE search: if i knew what to search for i wouldn't of asked the question :duh: - if its a commonly asked question maybe it should be in a 'sticky' thread?

thanks to those who replied with answer much apprechiated

Well, HDs have pretty much always been sold like that. This isn't anything new.


Disagree. It's just a basic computer knowledge question. If we make stickies for that, we'll also be making some on how to burn CDs and ISOs, and all the other countless n00b questions (no offense). There would be hundreds of stickies, kind of negating the point of having stickies in the first place.

Yep. Just like when a 20 GB HDD on a PC that was at the group home I used to be at 5 years ago was 18 GB, according to Windows.

btw, my 500GB is a 465Gb ^^

And my "160" GB drive is really only 148 GB.

The capacity of all hard drives are measured by the manufacturers using true SI (metric) nomenclature. In this system, there are 1000 unitsd in a kilo, 1000 kilo in a mega, 1000 mega in a giga, and so forth. Computers, however, are not based onthe base-10 arithmetic the SI system is. As such, the binary approximations are 1024 units in a kilo, 1024 kilo in a mega, 1024 mega in a giga, and so forth. The net result of this discrepancy in systems is that anything counted in SI units will always be larger than if it were counted in computer units.

For example, a 200GB hard drive is actually 200,000,000,000 bytes in size. In computer terms, this is 200,000,000,000/1024 = 195,312,500 kilobytes which is 195,312,500/1024 = 190,734 megabytes which is 190,734/1024 = 186 gigabyes. While it appears that 14 gigabytes dissappeared, nothing is actually is missing.

Understanding that factor, if you find you cannot account for some of the space used on your hard-drive, realize there are hidden system files and folders which you, the user, normally cannot access. Among these are the Recycler and System Volume Information folders. (The former is where anything you delete is stored until you empty the Recycle Bin and the latter is where Windows keeps its files necessary for System Restore. Since these folders can get quite large over time, it is advisable that you empty the recycle bin and restrict the amount of space Windows is given for the Ysstem Restore function.

Before anyone else replies my XXX GB HD is a really a YYY GB HD A short list of common values, courtesy of excel and 30 seconds of free time (quick and dirty unformatted copy/paste job):

GB GiB
20 18.62645149
40 37.25290298
60 55.87935448
80 74.50580597
120 111.758709
160 149.0116119
200 186.2645149
250 232.8306437
320 298.0232239
500 465.6612873
750 698.491931

Short version: You're "losing" roughly 7%.

As for space going missing (because of system restore, recycle bin and such) there's also the client side cache to blame (I've seen it enable itself and use up a few GBs before).