Not enough space to store temporary Windows installation files

I was trying to upgrade my system from Windows Vista to Windows 7 and I have got the following error. "There is not enough free space to store temporary Windows installation files. Try using Disk Cleanup, uninstall old programs, or move files to an external location such as a CD, DVD, or external hard drive." But there are about 225 GBs of free space. Can you guys direct me that where my machine could have problem due to which I am getting such faulty errors?

Upgrading a Windows XP to Windows 7 requires a custom installation that does not preserve programs, files, or settings. That's why we sometimes speak of new installation. Custom installation is more complex and may take several hours. You will need to move your files from your computer before installing Windows 7. To convenience, I recommend you download the program free transfer files and settings Windows, which require the use of an external hard drive. You'll find them in all electronic stores and office. It can easily increase the storage capacity of your computer. You must manually reinstall your programs after you install Windows 7.

This trouble occurs when it is the lively partition on the computer is a hidden partition. To install Windows 7 Setup program have to be transferred to the consequent definite files on the lively partition. Is this, however, a hidden partition, can not find the Windows Vista Setup the partition. I would like to ask you that you have made anything like this or not?

Be careful, be careful when installing special. HP has on different computers as first Partition a system called the partition with only 100 Mb, not for the new installation is meant to be a natural. Normally, the partition a drive letter is active, but not the primary boot partition! If the partition is damaged, should a return to the original state no longer be possible. Moreover, HP also note that, if not yet done so, as a precaution, the recovery disk to be created. If you want to play it safe, then the two or three disks (DVD) with the Recovery Manager (in Applications) to create. The course will not be needed if the system after installation permanently running properly.