1) Run Windows Update, install all available updates including the upgrade to IE8.
2) I suggest using Firefox rather than IE (but still keep your IE up to date)
3) For the stand-by problem, go to the advanced power settings. One way to get there is right-click the desktop and choose properties. Go to the screen-saver tab and there should be an option for power settings. I suggest using Hibernate rather than stand-by (either way, make sure u don’t use it so often that u forget to reboot, most problems I have experienced were solved by a simple reboot).
5) It could be you do have viruses, make sure your anti-virus program is running and up to date, run a full scan. I would also suggest running a scan with Malwarebytes Anti-Malware (Google mbam)
6) The newer versions of Flash give you the option to have it update automatically so you don’t ever have to bother with it again.
7) It could be that you do not have administrator privileges so Windows is not allowing Flash to install.
7) There is no number 4 so I added a 2nd number 7.