During the installation of ArcGIS Desktop on Windows 7 the RegistrySizeLimit key (HKLM\System\CurrentControlSet\Control) gets enabled and a value is set. This can result in 'Error 1450 Insufficient System Resources' messages when installing other applications that use a lot of registry space.
Another error that can occur:
Error: Error 1935. An error occurred during the installation of assembly 'Microsoft VC90.OpenMP,processorArchitecture="x86",publicKeyToken="1fc8b9a1e18e3b"