Allow USB debugging popup does not come in my new PC
<p>I am using a Nexus 10 Tablet( Android 4.4.4) . I have 3 PCs where I was already doing android development and one new PC on which I started today. All are windows 7 64-bit.</p>

<p>On the PC which I got today, I am using the same android-sdk, same google_usb_driver and the same platform tools(for adb), however in my newer PC, I am not able to go into adb shell.
The difference I see is that in my newer PC , I do not get the popup asking "Allow USB debugging" and when I do "adb devices", it shows the device as unauthorized.
Also when I do "adb shell", it gives the error message "This adb server's $ADB_VENDOR_KEYS is not set".</p>

<p>I went through various forums and tried the following:
1) Turning OFF and ON usb debugging and trying.
2) Doing "Revoke USB debugging authorizations".
3) Restarting my PC.
4) Deleting the C:\Users\UserName.android folder </p>

<p>However none of these worked. Also as I mentioned, it works absolutely fine on all the other PCs with the same device. This would indicate that something is missing/wrong in my newer PC.
One thing I was wondering is that when the dialog to "Allow USB debugging" comes up, it mentions that "The computers RSA key fingerprint is:xyz". Could it be that my new PC does not have some openssl or something like that which is causing some issue?
Also in my older PC, the .android folder has "adbkey" file, which is not present in the .android folder for the newer PC, could this in anyway lead to the problems or is it just a symptom of the problem and not the cause?</p>