On some environment (may be Production) you may run into a situation where you would not be able to run web services hosted in IIS. the error message would be something like below.
Server was unable to process request. —> Unable to generate a temporary class (result=1).
error CS2001: Source file ‘C:\WINDOWS\TEMP\4zbg-yjl.0.cs’ could not be found
error CS2008: No inputs specified
You get this error because IIS_WPG does not have Full Control access to the Temp folder so when you request a Web Service running on this machine, you get the above error. In most cases you would not see this kind of error because when you run ASPNET_REGIIS or if the Web Service sites are created by an application (BizTalk, etc), the corresponding security account is added to the C:\Windows\Temp with appropriate privileges (Full Control). If you give IIS_WPG Full Control permissions to the Temp folder, it will fix this issue.
Turlaps 
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Thanks! This worked for me.