windows sdk installation failed for windows xp and .net framework 4

Windows SDK (Software development kit) enables developer to create application and other essential IT supported features like windows troubleshooting platform (WTP) that can run on microsoft windows operating systems of different versions like windows 7/xp/vista etc.
To install windows sdk the system should need to have .net framework previously installed.Lets see what are error reports received while the windows sdk installation takes place on windows xp/ 7 operating systems.


Commonly occuring errors windows sdk installation:
Installation failed 
A problem occurred while installing selected windows SDK components.

• 'Installation of the "Microsoft .Net framework Reference Assemblies" product has reported the following error: Signature of the file netfx_dtp.cap could not be obtained.Possible unsigned file'.
•  Setup could not find the file WinSDKTools\WinSDKTools_x86.msi at any of the specified source locations.

SDKSetup_7.0.6918.0.log holds following error report :

• SchedNetFx:  Error 0x80070003: failed to call FindFirstFileW with string C:\WINDOWS\Microsoft.NET\Framework64\*
• SchedNetFx:  Error 0x80070003: failed to search for ngen under path C:\WINDOWS\Microsoft.NET\Framework64\
• SchedNetFx:  Failed to find 64bit ngen. No actions will be scheduled to create native images for 64bit.
•  Failed to download the file http://download.microsoft.com/download/A/6/A/A6AC035D-DA3F-4F0C-ADA4-37C8E5D34E3D/setup\MTPack\netfx_dtp.cab. Error - An exception occurred during a WebClient request.
• [SDKSetup:Error] Config_Products_Install: Installation of Product Microsoft .Net Framework Reference Assemblies (failed): Signature of the file netfx_dtp.cab could not be obtained. Possible unsigned file. Stack:    at SDKSetup.Utility.VerifyFileSignature(String LocalFile, Boolean QuietNoUI)   at SDKSetup.Product.CheckCABSignatures() at SDKSetup.Product.ProcessDownloadedFiles() at SDKSetup.Product.WaitForDownloadToComplete(ManualResetEvent cancelEvent) at SDKSetup.Product.ConfigureNewProduct(ManualResetEvent CancelEvent)
•  [SDKSetup:Error] Config_Products_Install: Windows SDK Setup (failed): Installation of the "Microsoft .Net Framework Reference Assemblies" product has reported the following error: Signature of the file netfx_dtp.cab could not be obtained. Possible unsigned file. Stack:    at SDKSetup.Product.ConfigureNewProduct(ManualResetEvent CancelEvent) at SDKSetup.Product.SetupProduct(TaskMode taskMode, ManualResetEvent CancelEvent) at SDKSetup.ProductCollection.SetupProducts(TaskMode taskMode, DownloadManager downloadManager, ManualResetEvent cancelEvent) at SDKSetup.ConfigProducts.DoCurrentTask(TaskMode Task).