Disk Space Errors on Dell Precision M70

TreeSize Pro.  C:\Windows\CSC.  Deleted d8, d7, d6, d4, d3.  System file warnings ignored.  Outlook had to be closed.  Unable to delete d5, d2, d1 due to open program and access errors.  A similar procedure was done on my office desk top machine a week or so ago by Rent-A-Geek – though she cut and pasted the folders to an external drive rather than deleting them.