We ran into an issue with some custom code that was doing a System.IO.File.Copy from a WebDav (SharePoint) to a UNC network share. Everything was working great until the file sizes we were transferring hit approx. 47MB in size. At this point, it craps out with an error.
When you upload a large file (over 50Mb usually) to SharePoint 2010, you might get an “Error 0x800700DF: The file size exceeds the limit allowed and cannot be saved” message. Check your current SharePoint file size upload quota and web.config settings. If the quota is not a problem, then the error is most likely caused by a local restriction set on Web Client service. By default, Web Client file size limit is set to 47Mb or so. To increase this limit:
- Backup the Windows Registry – be cool, keep your job
- Open Windows Registry using regedit command
- Browse to HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesWebClientParameters
- Right click on the FileSizeLimitInBytes and click Modify
- Click on Decimal, and type 4294967295 and click OK
- Restart Web Client service by typing services.msc.
p.p.s See my post SharePoint 2010 File Size Upload Limits – The Essential Mix for a full run down of all the file size limit jazz in SP 2010.