UAC stands for User Account Control (you should read this at some point since you're new to Windows 7 "Windows 7: User Account Control - UAC - Change Notification Settings") but that's not your problem.
Are you using IE, and if so, try using another browser (Chrome, Firefox, Opera, etc).
Have you tried disabling your security software, if not using Kaspersky, or booting in "safe mode with networking" if using Kaspersky? Some security software has a problem with the wrapper.
Have you scanned your PC for viruses and malware?
Have you installed all the required updates for Windows?
Finally, try booting in "safe mode with networking", download the current file and see if the file will unzip. If so, you've got something loading at normal boot that's causing an issue. If the problem lies with your security software then you can install the program; if the problem lies elsewhere then you should not install the program as it may be incompatible with something that normally runs and your PC might not start.