I enabled BitLocker last night. The computer understandably went incredibly slowly because of the heavy disk utilization while it was encrypting my drives. I let it run overnight, but this morning it still hadn't completed my boot SSD (120GB). My SSHD data drive (1TB) completed just fine. The SSD was at 85.4% complete at 10am, and at 1pm that had gone to 85.6%.

The computer is so slow as to be unusable. I managed to get a program installed (took an hour and a half) to check the SSD, it reported no problems. Windows system log shows no errors other than a TON of services that won't start. Task Manager shows no heavy use of any resource.

What could be the problem? Why is it taking so long to encrypt my SSD, and why is the computer unusable when supposedly no resource is being heavily utilized?