When I start LINQPad, I see a warning about assembly load times, suggesting that virus scanners are usually to blame.
This is a great feature that reveals otherwise hidden performance pitfalls. I would suggest that the message continue with one or two sentences about possible resolutions.
For example, virus scanners often allow a directory to be excluded from real-time scanning. Which directories might be added to improve assembly load times?
The software might also suggest searching online for higher-performance virus scanners, without recommending any in particular.