Are you receiving any malicious pop ups on the computer that the computer is been infected ?
Also provide some additional information like;
What is the operating system ?
Do we have a ny other antivirus installed in the computer
Well the operating system is a Windows vista,and yes there is pop-ups from Windows Security Center telling me to activate my anti-virus software
i dont have any other Antivirus software.
If your computer is already infected with a virus or other malware, this is supposed to happen while executing the file. I would recommend you stop the installation and run a scan for malware before attempting the install again.
The following document would help you in running an advanced scan, http://service.mcafee.com/FAQDocument.aspx?lc=1033&id=TS100054
Kindly report back if you have any issues.