Setting NTFS rights to deny Delete permission
Site expert Wes Noonan explains how to set NTFS rights on a Windows 2000 Advanced Server so that users are not able to delete files or folders, but they are able to save and make changes.
Traverse Folder/Execute Data
List Folder/Read Data
Read Attributes
Read Extended Attributes
Create Files/Write Data
Create Folders/Append Data
Write Attributes
Write Extended Attributes
Read Permissions
Change Permissions
You may or may not need all of the above permissions for your specific requirements. The key is to remember to NOT grant the "Delete Subfolders and Files" and "Delete" permissions.
Keep in mind that you may need to remove inheritance to allow you to make the necessary changes.