Under 'Scan Areas' select 'All harddisks', 'All removable media', 'Rootkits (full scan)', and 'Auto-start programs and modules loaded in memory'.

Under 'Full Virus Scan', click 'Settings'.

On the Avast main menu: click 'Protection'.

If you don't have an anti-virus program yet, or you want to check into free alternatives to the paid security software you now have, see my related article on Free Anti-Virus Programs before continuing. Click the desktop icon or the mini-icon in the task bar to open your program's main menu, then jump to the appropriate set of instructions. Below are step-by-step instructions for deep scanning with the most popular free anti-virus programs. There are many different anti-virus programs available, so it's not always obvious how to initiate a full anti-virus scan, and which options are important. If you're paranoid, or just have CPU cycles to burn late at night, schedule a deep scan to run weekly. Beyond that, a full scan once a month seems more than sufficient.

I would definitely recommend a full scan if you suspect that your system is infected.

These are standard features for almost all anti-virus software, even the free versions. How often should you run a full or deep scan? Most experts agree that a scheduled quick scan will do a good job of protecting you, if run on a daily basis, along with real-time malware detection. You can continue to work while the scan is in progress, but performance will probably take a significant hit due to the disk-intensive scanning operation. You should set aside at least two hours to allow a full system scan to complete. If a virus or rootkit is lurking anywhere on your hard drive, external drive, flash drive, or on a CD/DVD disk, a deep scan should find it.īecause it must open and scan through every file on every drive, a full scan will take a lot longer than a quick scan. Malware (viruses, spyware and other nasties) usually comes in the form of an EXE or DLL file, but it can also hide in a JPG file (graphics image), a DOC file (Microsoft Word), a PDF, and many other places you wouldn't expect. A deep scan will also scan your startup programs and the Windows registry for any traces of malware.

A quick scan examines only the most common spyware hiding places, such as the Windows system folders, your Documents and Settings folder, and the registry.Ī deep scan, sometimes referred to as a 'full scan', 'complete system scan', or 'whole computer scan' examines every bit of your computer's RAM memory, hard drives, and removable drives.

As you've noticed, the 'quick scan' option is the default in almost every anti-virus and anti-malware software.

Avast full scan time