Cannot download Google Play or use Android Market after factory restore on Dell Streak 7
I've had this problem after restoring my Dell Streak 7. I am working on a solution. There is no file manager by default so first search for and download ES File Explorer apk file. Also download Google Play Services apk file (about 42mb).
Email the ES File explorer to your gmail account. Once received you can install the apk from Gmail. Then connect the tablet to your PC via USB and copy the Google Play Services apk to your device. Use file explorer to find and install that apk file and it should work.