I would suggest that you remove the Avast AV and install Microsoft Security Essentials, if you say that you have errors then they cannot be that bad if the system still starts up and works correctly.
Once you have installed MSE then let it update and then run a full scan on your system, this might take a while to do
These entries in the registry could be broken links, have you been removing any software lately from your system?
Install MSE then post the results
DKTC
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