Not only does the boot up take long, but Lightroom Classic version 10.0 (202010011851-ef6045e0) is extremely slow. I have been a Lightroom user for many years and never had this problem. I have tried turning off the GPU option from Lightrooms preferences without any improvement.
My computer is running Windows 10 Business Edition Version 10.0.19041. System X64. Processor Speed 3.0GHz, Built in memory 16189MB. Memory cache size - 65.5MB.
Please post your System Information as Lightroom Classic (LrC) reports it. In LrC click on Help, then System Info, then Copy. Paste that information into a reply. Please present all information from first line down to and including Plug-in Info. Info after Plug-in info can be cut as that is just so much dead space to us non-Techs.