When using our components like  pdf split and merge in your ASP.Net application, you need to first set the working folder access to ensure the folder can be written in ASP.Net

 1. Using Windows Explorer, navigate to the working Folder (for example C:Inetpubwwwroot).

2. Right-click on the folder and choose Properties.

3. Select the Security tab. If you do not see the Security tab with Windows XP, you must disable “Simple File Sharing.” From the Windows Explorer menu choose Tools, Folder Options, View tab, and uncheck the Use simple file sharing (Recommended) option. This will enable the Security tab on file and folder property dialogs.

4. Look in the Group or user names list for aspnet_wp account (machine_nameASPNET) where machine_name is the name of your computer. If it is not present, click the Add… button and type ASPNET in the box and click the OK button.
Select the aspnet_wp account (machine_nameASPNET) user. Make sure the Allow check boxes are checked for the Modify and Write permissions. Click the OK button.