Reporting Services Service Pack 2 requires a reboot. Here's why.
When we started building the setup for SQL Server 2000 Reporting Services back in mid 2003, we started with a copy of the SQL Server 2005 (then called Yukon) setup code. While this seemed like a good idea at the time, it came with some baggage. It turns out that Yukon setup installed an early copy of the VS 2005 (Whidbey) C Runtime Library into the System32 folder. This early version had an VS 2003 filename (msvcr71.dll) but a Whidbey version number and was never formally released. We didn't discover this until the Reporting Services SP2 timeframe. As we never got a support call related to problems with this file, we think that it actually might be OK but leaving it there means that any patches to VS 2003 would not overlay this file (because of the Whidbey version number). Therefore, we decided to replace the file with the official shipping version in the SP2 setup. Unfortunately, the file is locked during setup, requiring a reboot at the end.
We realize reboots are a huge pain and apologize for the inconvenience but we felt it was the right thing to do.