If you are installing Visual Studio 2010 or Visual Studio 2010 Service Pack 1 from across the network and are experiencing slow install times, this could be caused by low network bandwidth and long verification times.
How to work around this issue
For Visual Studio 2010 RTM, copy the entire contents of the network directory locally. This directory contains setup.exe and folders like WCU. After all the files have been copied, run setup.exe as you would normally. When possible, you might also install from an ISO (if burning to DVD, please verify the download and burn results) or a web bootstrapper which should not exhibit this behavior to the same degree.
For Visual Studio 2010 Service Pack 1, you can either copy the entire contents of the directory containing setup.exe or run the web bootstrapper with additional command line parameters like:
VS10sp1-KB983509.exe /createlayout "%TEMP%Microsoft Visual Studio 2010 Service Pack 1_10.0.40219". Installing from an ISO/DVD or directly from the web should not exhibit this behavior to the same degree.
Description of the issue
Both VS2010 and VS2010 SP1 will first verify Authenticode digital signatures on executables, packages, and other supported file types before processing them or even copying them to the local machine. On slower networks, this means reading the file once to hash the image and verify it against the signed hash in the digital signature – even to get the digital signature – and again to copy the file or process directly. Once a local copy is made, performance of verification should be much less of an issue.
When installing from an ISO/DVD reading the file is most often faster (especially when compared to a slower network); and when downloading the file using the web bootstrapper – though download time is still a factor – the files are copied locally to disk (cached) before being read. This is why you might not see the same behavior for this specific issue when installing from an ISO/DVD or using the web bootstrapper.
Other potential performance issues
For VS 2010 SP1, some other potential causes of install performance issues have already been documented. One additional potential reason is that to mitigate setup failures we do attempt to install each package up to 3 times for certain error cases like files in use. You can help reduce slow install times in many cases by shutting down applications like Visual Studio 2010 or other applications that may use related runtimes like Visual C++ Runtime 10.0 and Visual Studio Tools for Office. In some other cases, users have reported temporarily disabling virus scanners having reduce setup time.