Is it normal for my computer to take longer to boot up after I install additional memory?

Yes, but no more than a second or two longer. The computer has to address the new memory installed, which can take a short time longer, depending on how much new memory was installed. If it is taking considerably longer, remove and reseat the memory module. On a Macintosh, try resetting the PRAM. If you continue to experience slow start times, please contact us.