Icon Source Root

Specifies the source location for an icon of a sequenced application package. Icon source roots support UNC and URL (http and https) formats. Example:
\\computername\sharefolder\resource or \\computername\content
http://computername/productivity/ or https://computername/productivity/
For example, you can use RTSP://SERVER:554 or HTTP://SERVER:80/CONTENT

For 4.5 and 4.6, UNC validation is performed:
\\Computer name is mandatory
May be an FQDN
May be an IP address
\Sharefolder is required
May be a drive specification (e.g. 'Z:')
\resource is optional
Leading and trailing whitespace is stripped
Trailing ‘\' inserted after path, if needed
So the resulting ISR setting for UNCs must be of the form: \\computer\sharefolder[\resource][\]

Icon Source Root

Registry Hive	HKEY_LOCAL_MACHINE
Registry Path	SOFTWARE\Wow6432Node\Microsoft\SoftGrid\4.5\Client\Configuration
Value Name	IconSourceRoot
Value Type	REG_SZ
Default Value