Hi i have recently had my computer rebooted and the hardrive been wiped clean and now have windows 7 where as previously I had XP. However I have had this problem for 2 weeks now and it is bugging me I have tried searching for solutions but i could not find any relating to windows 7 so hopefully somebody will help me. The problem is that when I download programs such as quicktimeplayer and try to install it the install does not start instead I get a message with a red circle and white cross that says - '' The windows installer service could not be accessed. This can occur if the windows installer service is not correctly installed. Contact your support personnel for assistance.'' This also happens when I try to install itunes Does anybody now how to solve this problem?? A similar thing also happened when I downloaded the driver and software for my logitech webcam and as a result I could not install them instead i got a message with a yellow triangle and an exclamation mark which said We were not able to install the software. This could be due to any of the following reasons: - Not enough disk space. Make sure yo have enough disk space on your computer to install this software (By the way I am pretty sure I have plenty of disk space available as i have jus got my computer rebooted.) - There is already another install in progress. Be sure that you are not trying to install other software at the same time. - You do not have permission to install software on this computer. Log in as an administrator or check with your computer's administrator. (By the way I am the administrator of the computer) - Your installation media is damaged .There may be some missing files . You can download the latest software from the logitech website ( I did download this software from the logitech website) - You can also restart your computerand attempt the software installation again. (No luck, same thing happens again with this same message popping up). My webcam is a logitech E3500. Secondly I have a HP Photosmart C4580 printer it is a wireless printer however when I tried installing it via a network my wireless network was not detected so I had to connect it via USB . I heard that i needed new drivers and software so i downloaded the software and drivers but i could not install them due to these same messages popping up. Could somebody pleeeeeease help me??? All help will be much appreciated!!!