When simply copying and pasting your code sample I get this errror:

Microsoft VBScript runtime (0x800A0046)
Permission denied
/pictures.asp, line 125

When trying to use your code in a page I wrote I get this error:

Error Type:
Microsoft VBScript runtime (0x800A0046)
Permission denied
/pictures_BK2.asp, line 187

I assume it is the same line:

Response.Write "<td>" & FormatNumber((folder.Size/1000),0) & " KB</td>"

Can you help me? Do I have to open permissions up on my default web folder? How do I do that?

Thanks!

You are getting this error because the folder this script is trying to read doesn't have READ permission for IUSR_MACHINENAME ( where MACHINENAME is the name of your computer ).

You'll have to give that folder READ permission for IUSR_MACHINENAME if you want your script to read it's contents. You can right-click folder name -> Properties -> Security tab -> Add permission for IUSR_MACHINENAME.