Here is a problem I’ve not seen before. A Lenovo Thinkpad E530 laptop running Windows 7, which after working fine for months developed a critical problem. On start up the user would see the network icon in the notification area (bottom right) show a busy icon or a red cross. No network connectivity, and the machine almost unusable.
After around 20 to 25 minutes the network sprang into life and everything was fine, until the next reboot when the problem repeated.
I fixed several errors in the event log to no avail. The problem persisted.
Went into msconfig and did the usual trick of disabling all non-Microsoft services and startup items. Everything worked fine. Laptop booted quickly and connected to the network.
What was the culprit? Trial, error and instinct eventually narrowed it down to an Intel service: Bluetooth Device Monitor. If enabled, 25 minute boot. If disabled, two minute boot.
I updated the Intel Bluetooth driver, a substantial 300MB download. This fixed it. I noticed that the updated Bluetooth Device Monitor now says it is from Motorola:
I understand it was always provided by Motorola but previously signed by Intel.
Posted here in case others run into this issue.
Update: this seems to be a common problem. It seems that a recent Microsoft update is incompatible with some versions of the Bluetooth driver. See here for discussion on the HP support forums, where it has occurred with the HP Probook 4540s and others.
As noted in the comments, I used Lenovo’s system update utility to grab the more recent “Motorola” driver. It shows there as an optional update.