Many programmers and some commercial firms have released products
designed to remove or block spyware. Steve Gibson's OptOut pioneered a
growing category. Programs such as Lavasoft's Ad-Aware SE (free scans
for non-commercial users, must pay for other features) and Patrick
Kolla's Spybot - Search & Destroy (all features free for non-
commercial use) rapidly gained popularity as effective tools to
remove, and in some cases intercept, spyware programs. More
recently[when?] Microsoft acquired the GIANT AntiSpyware software,
rebranding it as Windows AntiSpyware beta and releasing it as a free
download for Genuine Windows XP and Windows 2003 users. In 2006,
Microsoft renamed the beta software to Windows Defender (free), and it
was released as a free download in October 2006 and is included as
standard with Windows Vista. Additionally, Microsoft now provides
Windows Live OneCare with 90 days free trial download.Other well-known
commercial anti-spyware products include:

Malwarebytes' Anti-Malware (shareware, removes spyware for free, while
the paid version also protects, targets trojans and other malware many
programs miss)

PC Tools's Spyware Doctor (one free edition doesn't remove anything
but protects, the other free edition removes but protects partially
and uses a limited database)

DriveSentry (free version (3.1) will remove spyware)

SUPERAnti Spyware (free version fully detects and removes spyware, but
does not provide protection)

Sunbelt Software's Counterspy (15-day free trial)

Trend Micro's HijackThis (free)

Webroot Software's Spy Sweeper (free version does not remove spyware)

Major anti-virus firms such as Symantec, McAfee and Sophos have come
later to the table, adding anti-spyware features to their existing
anti-virus products. Early on, anti-virus firms expressed reluctance
to add anti-spyware functions, citing lawsuits brought by spyware
authors against the authors of web sites and programs which described
their products as "spyware". However, recent versions of these major
firms' home and business anti-virus products do include anti-spyware
functions, albeit treated differently from viruses. Symantec Anti-
Virus, for instance, categorizes spyware programs as "extended
threats" and now offers real-time protection from them (as it does for
viruses).

Recently, the anti-virus company Grisoft, creator of AVG Anti-Virus,
acquired anti-spyware firm Ewido Networks, re-labeling their Ewido
anti-spyware program as AVG Anti-Spyware Professional Edition. AVG
also used this product to add an integrated anti-spyware solution to
some versions of the AVG Anti-Virus family of products, plus made a
freeware AVG Anti-Spyware Free Edition available for private and non-
commercial use. This shows a trend by anti virus companies to launch a
dedicated solution to spyware and malware. Zone Labs, creator of Zone
Alarm firewall have also released an anti-spyware program.