A PowerShell (v2) script to iterate through a list of computers and identify manual mappings for each user profile. Hopefully, you've followed best practices and won't need to run this in your environment. ;)

Find Manual Drive Mappings

<#

Find Manual Drive Mappings

Created Mar. 19 2011 by Kai Mallea ([email protected])

License: http://www.opensource.org/licenses/mit-license.php
#>


# Newline-delimited file containing a list of computers to audit
$computers = Get-Content C:\Computers.txt

# File to output results to
$saveAs = 'D:\ManualMappings.csv'

# Iterate through all computers
foreach ($computer in $computers) {
    # Get all sub keys in HKEY_USERS
    try {
        $HKU = [Microsoft.Win32.RegistryKey]::OpenRemoteBaseKey('Users', $computer)
    }
    # If unable to remotely access registry note in output
    catch {
        "$computer,N/A,N/A,N/A,$_" | Add-Content $saveAs
        continue
    }
    
    # Move on to next $computer if no sub keys exist
    if ($HKU.SubKeyCount -le 0) { continue }
    
    # Filter keys containing 'Network' sub key
    foreach ($key in $HKU.GetSubKeyNames()) {
        $keys = $HKU.OpenSubKey($key + '\\Network')

        # Move on to the next $key if the 'Network' sub key is empty or non-existent
        if ($keys.SubKeyCount -le 0) { continue }
        
        # Iterate through each drive letter (a corresponding key name) and output drive mapping
        foreach ($driveletter in $keys.GetSubKeyNames()) {
            $values = $keys.OpenSubKey($driveletter)
            
            # Attempt to translate the SID into a friendly username
            try {
                $sid = New-Object System.Security.Principal.SecurityIdentifier($key)
                $user = $sid.Translate([System.Security.Principal.NTAccount])   
            }
            # Fallback to displaying SID
            catch {
                $user = $key
            }
            
            # Output result to file specified in $saveAs         
            "$computer,$user,$driveletter," + $values.GetValue('RemotePath') | Add-Content $saveAs
        }
    }
}