It is not uncommon for some security scans to take many hours while others finish quickly.
to complete an anti-virus or anti-malware scan depends
on a variety of factors
- The program itself and how its scanning engine is designed to scan: using a signature database vs heuristic scanning or a combination of both...see How an Anti-virus Program Works.
- Options to scan for rootkits, adware, riskware and potentially unwanted programs (PUPS).
- Options to scan memory, boot sectors, registry and alternate data streams (ADS).
- Type of scan performed: Deep, Quick or Custom scanning.
- What action has to be performed when malware is detected.
- A computer's hard drive size.
- Disk size and used capacity (number of files that have to be scanned).
- Types of files (.exe, .dll, .sys, .cab, archived, compressed, packed, email, etc) that are scanned.
- Whether external drives are included in the scan.
- Competition for and utilization of system/CPU resources by the scanner.
- Other running processes and programs in the background.
- Whether the scanning engine stalls, hangs or freezes.
- Interference from malware.
- Interference from other security programs attempting to scan at the same time.
- Interference from other programs attempting to update (download/install) components from the Internet.
- Interference from the user (whether or not you use the computer during the scan).
In most cases when performing routine security checks, only a Quick Scan is needed
since it checks the areas of your computer most likely to contain malware...the most prevalent and common places where malware typically hides. A Full Scan
is much more comprehensive and can take a long time since it checks the entire hard drive (all folders/files) which can number in the thousands. The length of time for performing this type of scan varies because it is so comprehensive and therefore can take several hours. As such, a Full scan is generally recommended only for heavily infected systems...showing obvious indications (signs of infection
and malware symptoms
) that something is wrong.To speed up a scan
, clean out temporary (junk) files
first, temporarily disable any other real-time protection tools
, close all open programs, perform a Quick Scan
instead of a Full one and do not use the computer during the scan
. You can also speed up a scan by using file exclusions...What Files Should You Exclude?