Symptoms
Having trouble logging onto websites
My computer is running super slow
Avast and Malware not finding any viruses
Avast message, “some files could not be read”
I received a Microsoft pop up warning, “some of my software may not be invalid”
Any help is greatly appreciated.
hey could you show a picture of that avast says.
if you think your infected please attach the logs from this guide.
a malware expert will help you from there.
Haha, Java was the Number 1 most exploited program in the last 2 months, they quickly updated it, but I’m not sure whether its reliable or not. Best to disable Java plugin for the moment 
Avast message, "some files could not be read"file(s) that can not be scanned (reason given by avast) are just that, it does not mean they are infected.....just a scan error report
Here is the list of files that Avast could not read.
Most of the files are what Pondus said in the reply above. Others file location and reason why they were not read is not visible in your screenshot; However your las image gives reazon to believe something is not right with Avast! or your sys.
Repair Avast!
With XP
Start > Control panel > Add & Remove programs > select avast! and click " Change/Remove ". Look for " Repair " and click it.
With Vista or win7
Start > Control Panel > Programs > Programs & Features > uninstall a program > select avast! and click " Uninstall/Change ". Look for " Repair " and execute.
Reboot when finished.
See how it behaves if still have problems follow mikaelrask above. Instructions:
Follow this guide: http://forum.avast.com/index.php?topic=53253.0
and attach ( Do not copy/paste ) logs for AdwCleaner, malwarebytes’, OTL, and aswMBR.exe here:
where an expert in the removal of malware will help you.