My Nexus 5 was a Telstra variant (KTU84Q) which wouldn’t get the OTA, and I was just sick of waiting. So this is how I side loaded the OTA update for Lollipop (LRX21O)
This is the TL:DR version
I followed this guide
http://ausdroid.net/howto/side-load-ota-update/
I got my Nexus 5 OTA update for the Telstra version (KTU84Q to LRX21O) from
http://ausdroid.net/2014/11/13/android-lollipop-ota/
If you don’t get the KTU84Q to LRX21O version it won’t work.
As windows driver discovery is just rubbish, I manually installed the Nexus 5 windows 7 USB driver (from device manager –> update driver) which was downloaded from
http://developer.android.com/sdk/win-usb.html
I then had to reinstall the USB driver when the device went into bootloader mode. The device changes its USB hardware ID when it is in bootloader mode. the following fixed it for me.
http://blog.dantup.com/2012/10/fixing-adb-device-not-found-with-nexus-7-in-recovery-mode/
Uploaded the image, did a reboot, all the apps upgraded and vola.