Deep scan vs file and folder scan

I performed Deep Scan several times for the past week and results indicated No Threat, however couple days ago i performed File and Folder scan immediately after Deep scan and discovered few Threats and quarantine. Why Deep scan missed to detect threats.

Greetings,

We're glad to look into this & help you.
Deep Scan is a predefined, in-depth scan of your system that checks your storage drives and memory for malware (including rootkits).
Whereas, File or Folder Scan, scans the folders you select when you initiate the scan. 
You can also scan a specific folder by right-clicking the folder in File Explorer or on your Windows desktop and selecting Scan selected items for viruses.
From your description, it seems that location that you've scanned using File or Folder scan isn't included in the Deep scan parameters (scan area).
You can check this article which helps to manage scan settings & include the desired areas to be scanned. 
For further queries, feel free to write back to us.

Thank you for your prompt reply.
i thought deep scan supposed to scan all files and folders in harddrive, i have ticked All files in the scan parameter . The infected files were discovered in  Appdata file in C drive. 
i have replied your email with the screen shot attachment and more description,  not sure if you received.
If the scan missed to detect infected files, does AVG real time protection able to protect the computer from attacking by malwares or virus ?

Greetings,

We're glad to look into this & help you.
Deep Scan is a predefined, in-depth scan of your system that checks your storage drives and memory for malware (including rootkits).
Whereas, File or Folder Scan, scans the folders you select when you initiate the scan. 
You can also scan a specific folder by right-clicking the folder in File Explorer or on your Windows desktop and selecting Scan selected items for viruses.
From your description, it seems that location that you've scanned using File or Folder scan isn't included in the Deep scan parameters (scan area).
You can check this article which helps to manage scan settings & include the desired areas to be scanned. 
For further queries, feel free to write back to us.

Thank you for writing back to us again.
We have sent you an email asking you to connect with our AVG free remote technician so that they will check and help you to resolve this issue.
You can also reply to that email for further assistance.
Thank you.

Hi, 
l am having issue with my current laptop ( 12 years model) on Screen shot, unable to capture after many tries. I am thinking of transfering my AVG account to a new laptop. Does AVG Internet Security keeps the old records such as quarantine items  so that i can made screenshots for you. Plesae advise. Or is there other way that i can do to send the screenshot.

Thank you for writing back to us.

We understand your concern. Please rest assured, as your AVG Internet Security blocks viruses and malware in realtime, keeps your emails secure, protects your personal files, passwords, and webcam from hackers, and lets you shop and bank online without worry.
As we couldn't locate any previous contact/tickets under your account, we request you to share us screenshots of the detected threats over this post.
Also, please attach a screenshot of your Deep scan parameters.
You can post the screenshot here in your topic. Click on Answer & then click on the Image [mountain symbol] & follow the instructions.
Note: Kindly click on "See Details" on the threat pop-up and then share us the screenshot.
Thank you for understanding in advance!