Change a script to check remaining space of a drive - vbscript

Question

I currently have this VBScript, which checks the size of a folder, then deletes files (oldest first) until a threshold is reached.
Option Explicit
'use next line for production
On Error Resume Next
'use next line for debugging
'On Error GoTo 0
Dim strResult: strResult = Wscript.ScriptName
Dim objFSO, strOldestFile, dtmOldestDate, strFolder, oFolder, intFolderSize
Set objFSO = CreateObject("Scripting.FileSystemObject")
dtmOldestDate = Now
strFolder = "C:\Users\PLEX\Downloads\Torrent\"
strOldestFile = ""
Set oFolder = objFSO.GetFolder(strFolder)
intFolderSize = Int(((oFolder.Size / 1024) / 1024) / 1024)
Do While intFolderSize >= 110
strOldestFile = ""
dtmOldestDate = Now
FindOldestFile oFolder
'WScript.Echo strOldestFile
objFSO.DeleteFile strOldestFile, True
strResult = strResult & vbNewLine & dtmOldestDate & vbTab & strOldestFile
intFolderSize = Int(((oFolder.Size / 1024) / 1024) / 1024)
Loop
'WScript.Echo strResult
WScript.Quit
Sub FindOldestFile(objFolder)
Dim objFile, colFiles, colFolders, strFile, dtmFileDate
'find oldest file
Set colFiles = objFolder.Files
For Each objFile In colFiles
strFile = objFile.Path
dtmFileDate = objFile.DateCreated
If dtmFileDate < dtmOldestDate Then
dtmOldestDate = dtmFileDate
strOldestFile = strFile
End If
Next
'recurse subfolders
Set colFolders = objFolder.SubFolders
For Each objFile In colFolders
FindOldestFile objFile
Next
End Sub
Currently this script will:
Check the capacity of folder A including all subfolders.
Delete files (oldest first) from folder A and subfolders until a threshold is reached (in this case, 110GB)
I'd like to modify the script to do this:
Check the capacity of folder A including all subfolders.
Delete files (oldest first) from folder B (which is a subfolder of folder A) and subfolders until a threshold is reached.
For example, is it possible to get this script to check the used capacity of the entire C: drive and delete the oldest files from C:\Users\PLEX\Downloads\Torrent\ when there is less than 5% remaining on C:?
Edit: I already had full access, and fixed the error by changing C:\ to C: . I also changed C:\Users\PLEX\Desktop\New Folder to \Users\PLEX\Desktop\New Folder and am now getting no errors. The only problem is that IntFolderSize still shows the size of my subfolder, not the root. I've confirmed that by using Wscript.Echo intfoldersize. My current script is below. How can I get IntFolderSize to show the used size of the root?
option explicit
'use next line for production
'On Error Resume Next
'use next line for debugging
'On Error GoTo 0
Dim strResult: strResult = Wscript.ScriptName
Dim objFSO, strOldestFile, dtmOldestDate, strFolder, oFolder, intFolderSize
Set objFSO = CreateObject("Scripting.FileSystemObject")
dtmOldestDate = Now
strFolder = "C:"
strOldestFile = ""
Set oFolder = objFSO.GetFolder( strFolder)
intFolderSize = Int(((oFolder.Size / 1024) / 1024) / 1024)
Wscript.Echo intfoldersize
Do While intFolderSize >= 70
strOldestFile = ""
dtmOldestDate = Now
FindOldestFile objFSO.GetFolder(objFSO.BuildPath(strFolder,"\Users\PLEX\Desktop\New Folder\"))
'wscript.echo strOldestFile
objFSO.DeleteFile strOldestFile, True
strResult = strResult & vbNewLine & dtmOldestDate & vbTab & strOldestFile
intFolderSize = Int(((oFolder.Size / 1024) / 1024) / 1024)
Loop
'Wscript.Echo strResult
Wscript.Quit
Sub FindOldestFile( objFolder)
Dim objFile, colFiles, colFolders, strFile, dtmFileDate
' find oldest file
Set colFiles = objFolder.Files
For Each objFile in colFiles
strFile = objFile.Path
dtmFileDate = objFile.DateCreated
If dtmFileDate < dtmOldestDate Then
dtmOldestDate = dtmFileDate
strOldestFile = strFile
End If
Next
' recurse subfolders
Set colFolders = objFolder.SubFolders
For Each objFile in colFolders
FindOldestFile objFile
Next
End Sub

Answer 1

Change
FindOldestFile oFolder
into
FindOldestFile objFSO.GetFolder(objFSO.BuildPath(strFolder, "sub\folder"))
where strFolder is your root folder and "sub\folder" the relative path to the subfolder below that root folder.
Edit: Note that the oFolder.Size property will raise an error unless you have access to every single file and folder below oFolder. If you want to check the free diskspace on the volume anyway, you may be better off using WMI for that and using oFolder strictly for the folder you want to delete from:
strFolder = "C:\Users\PLEX\Desktop\New folder"
Set oFolder = objFSO.GetFolder(strFolder)
threshold = ... 'desired minimum free diskspace in byte
Set wmi = GetObject("winmgmts://./root/cimv2")
qry = "SELECT * FROM Win32_Volume WHERE DriveLetter='C:'"
Do While wmi.ExecQuery(qry).ItemIndex(0).FreeSpace < threshold
...
FindOldestFile oFolder
...
Loop