Numerous Problems Since Latest Update

Over the past several days I have been having problems with the following:

1) The Welcome Center window opens however the icons or center portion of
the window doesn't come up. It is like it has been paused in the middle of
startup. The only way for me to get rid of this window is through
Ctl+Alt+Del.

2) The Clock and image in the upper right hand side of my desktop never
comes up. This wasn't a problem a few days ago.

3) I cannot delete an .avi file to my recycle bin. A window comes up and
states the file is already in use/open in another program.

4) When I close down my computer a window pops up and states that Program
Manager is preventing your computer from shutting down. I can click on the
logoff button from there and it will shut down.

5) Several of my jpg and pdf images do not show up or "reveal" themselves in
icon mode. They do open up. This only started a few days ago as well.

6) A McAfee window now opens upon startup that states a Buffer Overflow
Blocked - File C:\windows\system32\DII Host.exe.

7) "Windows Explorer is not responding" when I close down the Welcome Center
window.

8) I ran sfc /scannow (per another suggestion given to me) and it came back
with "Windows Resource Protection found corrupt files but was unable to fix
some of them. The details are included in the CBS.Log however I cannot
access this notebook.

I am by no means an expert in computing so any "dumbed down" help will be
greatly appreciated. Thank you!

BK