How to get SVG thumbnails in Windows Explorer?

Use this awesome SVG thumbnail shell extension which works fine in Windows 7 & Windows 8 & Windows 10 (both 64-bit and 32-bit):

Extension module for Windows Explorer to render SVG thumbnails, so that you can have an overview of your SVG files.

It is open source and free - what more can you ask for?

If you still have problems to view the thumbnails after installing this shell extension please refer to these instructions how to reset your icon cache in Windows 7/8.

On Windows 10 after installing try changing your SVG file association (the "Open With"). By changing it something somehow gets refreshed and it starts working.

In regards to the answer given by geo, in the event someone needs to rebuild the IconCache.db and wants to give a go at not needing to reboot try the following batch.

@ECHO OFF

TASKKILL /IM explorer* /F
DEL "%localappdata%\IconCache.db" /A
explorer.exe

Adobe Illustrator isn't the only way to do this, nor is it the best way to do this.

See the post by @Deckard above...

Follow the link he provided to the SVG Explorer Extension. Download and install Dotz Software SVG Explorer Extension, aka DSSEE.

Once installed, open Task Manager and kill all instances of explorer.exe. From the Task Manager menu, choose File->Run new task menu. In the dialog box, simply type explorer and hit OK.

NOTE: Please do the above step only if you're comfortable with killing and restarting processes through the Task Manager. If not, then simply reboot your system so that the new explorer extension can load.

From then on, all SVG images will show up as thumbnails in Windows Explorer.

This extension has worked perfectly for me on both Win7_x64 and Win8_x64! In fact, I was recently pleasantly surprised to learn that it displays thumbnails for compressed SVGZ images as seamlessly as it does the non-compressed versions.

NOTE (2014/07/17):

Per the comment by John Rasch, if you can't see the SVG thumbnails after following the steps above, you can clear your icon cache using the following batch file:

@ECHO OFF

TASKKILL /IM explorer* /F
DEL "%LOCALAPPDATA%\IconCache.db" /A
shutdown /r /f /t 5 /d 02:04

Copy this to RebuildIconCache.bat and run it as Administrator. It will kill all Windows Explorer processes, which is required before you can delete the icon cache, then delete the icon cache, and, finally, reboot your system.

EDIT (2015/12/08):

As noted by @user1698811 below, the last line, "shutdown /r /f /t 5 /d 02:04", can simply be replaced with "explorer.exe", getting rid of the need to reboot.

EDIT (2015/03/10):

I know this question was asked about Windows 7, but I thought it would be useful to add instructions for Windows 8 and above...

Windows 8 introduced a new icon and thumbnail cache system. Instead of a single file containing the entire icon cache, Windows 8 uses multiple cache files, based on the size and type of icon. These files are stored in "%LOCALAPPDATA%\Microsoft\Windows\Explorer". As an example, that directory on my system includes the following files:

iconcache_16.db         thumbcache_16.db
iconcache_32.db         thumbcache_32.db
iconcache_48.db         thumbcache_48.db
iconcache_96.db         thumbcache_96.db
iconcache_256.db        thumbcache_256.db
iconcache_1024.db       thumbcache_1024.db
iconcache_exif.db       thumbcache_exif.db
iconcache_idx.db        thumbcache_idx.db
iconcache_sr.db         thumbcache_sr.db
iconcache_wide.db       thumbcache_wide.db

As a result, in order to clear the icon cache in Windows 8 or above, you would need to delete all of the 'iconcache_*.db' files in the above directory.

Note that, in addition to the above files, Windows 8 still retains the "%LOCALAPPDATA%\IconCache.db" file. I honestly don't know if this file is used or not, but, to be thorough, it would be best to continue to delete that file as well.

Therefore, for Windows 8 and above, we have the RebuildIconCache8.bat file as follows:

@ECHO OFF

TASKKILL /IM explorer* /F
DEL "%LOCALAPPDATA%\IconCache.db" /A
DEL "%LOCALAPPDATA%\Microsoft\Windows\Explorer\iconcache_*.db" /A
shutdown /r /f /t 5 /d 02:04

or as @user1698811 suggested:

@ECHO OFF

TASKKILL /IM explorer* /F
DEL "%LOCALAPPDATA%\IconCache.db" /A
DEL "%LOCALAPPDATA%\Microsoft\Windows\Explorer\iconcache_*.db" /A
explorer.exe

which resets the icon cache without having to reboot.