Most of the user installed OS in C: due to some insufficient space some of the app may stuck during installation.
here is the solution for you
As the size of hardrives increase, more people are using partitions to seperate and store groups of files.
XP uses the C:Program Files directory as the default base directory into which new programs are installed. However, you can change the default installation drive and/ or directory by using a Registry hack.
Run the Registry Editor (regedit)and go to
Start–>Run–>regedit
HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersion
Look for the value named ProgramFilesDir. by default,this value will be C:Program Files. Edit the value to any valid drive or folder and XP will use that new location as the default installation directory for new programs.
Happy Customizing !!!

