The difference not a lot but still like to know why? My HD is 40GB but in XP it read only 38GB My XP say 15 GB free but when I enter command prompt though xp - It read 17 GB free which include the 2 missing GB in xp. was wondering if I had format wrongly last time round resulting in the missing HD space. any way to check? Tks.

The true size of the disk will not be 40GB. It will be 40,000MB (or something near that value). Therefore because 1GB is 1024MB the disk will be read as about 38-39GB. What you are seeing in the command prompt will more than likely be in MB not GB. If you are reading it as 17,000MB then that will translate to about 15GB accounting for odd values. My 160GB hard disk only shows up as 149!

For me, I think the HD does show as 40GB before then I format it and afterwards It became 38 GB if I remember correctly. If 1 GB is 1024 MB then why 40 GB is less than 40000 MB ? Tks.

read though the forum...seem like It's a sticky problem. It's just like that.

Hi Sunny, No it is not a sticky problem. As an FYI, it's Decimal versus Binary. For simplicity and consistency, hard drive manufacturers define a megabyte as 1,000,000 bytes and a gigabyte as 1,000,000,000 bytes. This is a decimal (base 10) measurement and is the industry standard. However, certain system BIOSs, FDISK and Windows define a megabyte as 1,048,576 bytes and a gigabyte as 1,073,741,824 bytes. Mac systems also use these values. These are binary (base 2) measurements. i_XpUser