If you're have more than one computer and want to apply the reference file updates to the other computers (without downloading them again from each computer within a Workgroup / SOHO), try this:
Lavasoft Ad-Aware - http://www.lavasoftusa.com
When you download the reference file update using Ad-aware, it's stored in C:\Program Files\Lavasoft\Ad-Aware SE Personal folder with file name "defs.ref". You may just use the web-update feature in Ad-aware from one system. Then, transfer this reference file within your Workgroup computers. Placing this .ref file in the Ad-aware folder will be enough.
Or, to download the reference file in Zip format from Lavasoft website, visit their downloads page and look for the section "UPDATES AVAILABLE" and download the latest definition file available there.
Note: The above information applies to Ad-aware build 1.3. Earlier versions of Ad-aware uses the filename reflist.ref. http://www.lavasoft.de/ms/faq-ref.htm
SpyBot Search & Destroy - http://www.safer-networking.org/en/download/index.html
Download the Detection updates from http://www.safer-networking.org/en/download/index.html
Spyware Blaster - http://www.javacoolsoftware.com/spywareblaster.html
Click the Updates menu in the left, and click the button Check for Updates. Download the updates using that feature. To share the update to another systems running the same version of Spyware Blaster, copy all the *.DTB files (namely sbdatabase.dtb, sbdatabase2.dtb, rsdatabase.dtb, ckdatabase.dtb, sbinfo.dtb) to the other systems. This information applies to v3.2 of Spyware Blaster.
After copying the files, to verify if the database is current in the other systems, open Spyware Blaster in those systems and note down the line SpywareBlaster database loaded <date>