hey i was wondering if avast default settings are good enough or do i have to make some changes to them ?
also i wanted to know that it gives an option to “scan whole files (may be slow for very big files)” and “scan for PUP’s” which are not by defaul on…should i turn them on ??
Well, you need to get used to avast or take some time to learn it.
If you can’t, let the default settings. They’re thought to be a good balance between performance and protection and suitable for non-technical users.
But, if you want, you can check both of that options 
I think you just need to turn on PUP Scan .That scans any unwanted keylogger programs!
First…welcome to the forum. That said for a “newbie” I would suggest using default settings for now. When you are more acquainted with avast then you can always “create” a custom scan. But for now default settings are good. PUP (potentially unwanted programs) are pretty much root-kits. I have them on, some leave them off. I would strongly urge you to leave the “packers” settings alone. As far as frequency of scans some scan once a week, others more often. Personally I run a full system scan two times a week with a quick scan every other day. Other software which you may find useful are malwarebytes and super anti-spyware.
http://filehippo.com/download_malwarebytes_anti_malware/
http://filehippo.com/download_superantispyware/
Hope this helps.
PUPs are NOT ‘pretty much rootkits,’ they are what it says on the tin, Potentially Unwanted Programs. Rootkits really aren’t programs that are unwanted as they generally aren’t installed by the user, but there are programs that use rootkit style functionality to protect themselves, etc…
Many tool which can be used for good or evil fall into that category as if installed by the user not a problem (it is serving its good purpose), if it wasn’t installed by the user then it is more likely to be unwanted.
Switching on PUPs during scans, does require an amount of knowledge of what is on your system and why it might be considered a PUP as you will have to make an informed decision when avast alerts should it find one.
PUPs are NOT ‘pretty much rootkits,’ they are what it says on the tin, Potentially Unwanted Programs. Rootkits really aren’t programs that are unwanted as they generally aren’t installed by the user, but there are programs that use rootkit style functionality to protect themselves, etc…
Sorry DavidR, but I have seen both terms being used in the same manner. Thanks I learned something new.