[Closed] cannot install Kaspersky IS 2009

Hi! This is my girlfriend's computer. She has been using this pc and accessing the internet without any antivirus software. Flash drives are inserted every now and then. This pc contains a lot of malwares especially viruses, I think. I have tried to install Kaspersky Internet Security 2009, but the installer ends without prompting anything. This might be caused by the virus. I have also tried to start this machine in Safe Mode. Still, the same outcome. What can you suggest? Her siblings need their files, but no backup. I can't just reformat the harddisk. What should I do? Any help would be greatly appreciated. Thank you in advance!

If you still need help, Scan again with HijackThis, and "copy/paste" a new log file into this thread.

Also please describe how your computer behaves at the moment.

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