try to completely uninstall both intel and amd drivers, and install the latest of both again, that should work i suppose..
i have latest intel drivers and amd 13.1, and here's what my device manager says:
*i.imgur.com/Rkd9c9h.jpg
download from here: *www2.ati.com/DriverS/mobile/13-1_mobility_vista_win7_win8_64_dd_ccc_whql.exe
.
well, i never installed DELL's graphics driver on my win8, only installed intel's drivers from intel's site and amd's drivers from amd's site, and have no problem till date in switchable graphics..
And how can you say that AMD drivers will screw switchable graphics??? 13.1 drivers actually improves Enduro rather than screwing it..
well, flipkart is not a reliable source for the specs, you have inspiron 15r, so some drivers should be same as in 15r turbo, so lemme give you some links:
Intel GPU: *downloadmirror.intel.com/22374/a08/Win32_152812.zip
AMD GPU: *www2.ati.com/DriverS/mobile/13-1_mobility_vista_win7_win8_32_dd_ccc_whql.exe
Bluetooth: *downloadmirror.intel.com/22422/eng/BT_2.6.1211_s32.exe
Wifi: *downloadmirror.intel.com/22116/eng/Wireless_15.3.1_Ds32.exe
Wifi: *downloadmirror.intel.com/22116/eng/Wireless_15.3.1_s32.exe (download both wifi)