"error 1304. error writing to file" can't install

At present I am having a desktop running with Windows XP Home and Office 2003 student edition. Recently I thought to upgrade to Office 2007 and hence bought a copy. As I am not a pro in all these things, I started the installation I chose to upgrade (like I do with other softwares, just upgrade if there is any new version available), Installation went for a minute and stopped suddenly giving me an error message saying:

"Error 1304.
Error writing to file C:\WINDOWS\System32\WISPTIS.EXE"

As I said I don’t have much knowledge I tried searching web for any solution but dint got according to my situation hence I decided to try the installation again by selecting ‘Custom’ this time from the installation wizard. I did the same but this time it gave some another error. It is the following:

"Error 1712.
One or more files required to restore your computer to its previous state could not be found restoration will not be possible."

This was too frustrating me. I don’t know how to fix it or what could be the reason for this error but there is one thing coming to my mind. Is it because my drive is NTFS, and do office require FAT32 file system ? if it is so, I have a portable drive that is with FAT323. Can I install Office 2007 on my Portable HDD and use it on my computer ?Please help me out of this.

First of all there is nothing like NTFS or FAT32, instead it is good you have NTFS as it is the newer file system. Furthermore, on many occasions upgrading office with existing installed office program create conflicts between registry keys. Hence if the installation went fine (in some cases, well and good) but if you faced any error, you must remove the earlier office and than install the new one.

Here what you need to do is Uninstall Office 2003 completely from the system. Start Disk Cleanup Wizard and delete each and every file you see related to the same. Restart the computer, login with user account having complete Admin Access and start the new installation. This time it should not give you any error message.

Thanks for the tips buddy. That was really helpful and I already did it before reading this. As I was trying out whatever I could do, I thought to give a try installing after removing Office 2003 and later my new installation went fine without any problem. But thanks to you anyway. :)