IE9 Email/Update Issues

Hello IE forum.

Recently, my father has been having issues with IE9 not allowing him to check his emails (Hotmail specifically) or utilize certain websites. I've tried uninstalling IE9 and downgrading to IE8, but there was no success. Should I update his laptop to IE10 in an attempt to resolve this issue? It should be mentioned that shortly before this started happening, there was an instance where Norton AV popped up and said that it blocked something malicious. Afterwards, the odd behavior started up. I'm not entirely sure if this points at something that could be malware-related or not, since I've run several scans and have come up with nothing. At any rate, any help would be greatly appreciated. Thanks!