Jenkins hanging at "Fetching upstream changes from origin"

I'm trying to set up Jenkins on a Windows Server 2012 machine, and I'm having a lot of difficulty.

Things I've done:

• Created a password-less id_rsa, and id_rsa.pub
• Created a known_hosts file for bitbucket.org using ssh.exe -T bitbucket.org and accepting to add the host.
• Added E: to System-wide HOME Variable
• I've added those files to C:/Windows/SysWOW64/config/systemprofile/.ssh as well as E:/.ssh
• I've linked my public key to Bitbucket as a deployment key.
• I've triple-checked all my URLs, usernames, etc.
• I've even manually pulled from the repository to setup an initial base in C:/Program Files (x86)/Jenkins/jobs/MyProject/workspace/

And yet it still hangs at

Building in workspace C:\Program Files (x86)\Jenkins\jobs\MyProject\workspace
Checkout:workspace / C:\Program Files (x86)\Jenkins\jobs\MyProject\workspace - hudson.remoting.LocalChannel@13ca972
Using strategy: Default
Fetching changes from 1 remote Git repository
Fetching upstream changes from origin

I've given it about 20 minutes, so it's not a speed / size of the repo issue. If I cancel, this is what is returned:

ERROR: Problem fetching from origin / origin - could be unavailable. Continuing anyway
hudson.plugins.git.GitException: Error performing command: C:\Program Files     (x86)\Git\bin\git.exe fetch -t origin +refs/heads/*:refs/remotes/origin/*
at org.jenkinsci.plugins.gitclient.CliGitAPIImpl.launchCommandIn(CliGitAPIImpl.java:780)
at org.jenkinsci.plugins.gitclient.CliGitAPIImpl.launchCommand(CliGitAPIImpl.java:739)
at org.jenkinsci.plugins.gitclient.CliGitAPIImpl.fetch(CliGitAPIImpl.java:160)
at hudson.plugins.git.GitAPI.fetch(GitAPI.java:230)
at hudson.plugins.git.GitSCM.fetchFrom(GitSCM.java:793)
at hudson.plugins.git.GitSCM.access$000(GitSCM.java:57)
at huds