Drive C: getting smaller.

[#1]

Any ideas why the windows XP partition would fill up very quickly from about 4Gb to almost 10Gb?
I am unable to check for what files are filling up the drive as a restore has been preformed and the drive is back to normal size at the moment.

[#2]

Can you just clarify if the drive size is getting smaller or the available space? (I'd assume its the latter but your title makes it sound like the former!)

[#3]

What is the C: partition size and does your internet security package create activity logs

[#4]

Sorry. It is the available space. Partition is 10Gb on a 40Gb disk. The computer is runing AVG Free and Zone Alarm Free. I have used this software for years without any problems.
The problem is not with my computer but a friends.

[#5]

As a first shot try following the recommendations in this thread

[#6]

The main offender are
Temp files
Temporary INTERNET files
Software thats installed and leaves its install behind like photoshop you download a 400 meg file and when you install it it extracts the files from the 400 meg and leaves it on the disk so you get 400 meg file 700 meg extracted and then 600 meg of the software there are a few programs that do that.
The pagefile growing as the mft is full.
System restore of coarse
The hard drive has been corrupted and its recovered some of the files when chksdk has run.
The hard disk is corrupt and reporting the usage wrong
SP3 download and install?
Windows update
logs from any software but as most of these are txt they dont normally take up much room.
This is the sort of problem you get if you run your own pc repair company were do we send the bill for the consultancy?

[#7]

I have had Adobe Photoshop crash when doing some batch work, and it left a 1.5G - yes Gig file in the temp folder !!.

[#8]

We had a similar problem on a work PC .. turned out to be the IIS logs.
So if you use that, then it's something else to check.

[#9]

You don't say if your friend uses different partitions for data.  MSWindows in its wisdom saves all application data in C:\ drive by default.  Unless you configure each individual application's properties to set a path to a partition outside C:\ then you will soon discover that it will fill up.  The more common culprit is ipod which along with iTunes saves everyting on C:\ - a few albums or movies later you're choca.
Also, BBC's iPlayer and Ch4's 4oD will by default save everything on the C:\ drive.  You can change iPlayer's storage path, but not 4oD's.
HTH.