@@ gaurav...kidnly try to do the following:
CPU hsf area:
1st: Clean the hewat sink...remove as much dirt from the fins, top fan. Remove the old thermal paste .If possibel clean the base of heast sink,ie the are which makes contact with cpu with rubbing alcohol/surgical spirit for ur chemist.If you fail to procure the same, dab some aftershave on a cloth and clean the surface.
Same for your cpu heat spreader section, ie the the top of the cpu.Clean the surface.
If you feel uncomfy about liquid cleaning part, just make sure both surfaces are free from oil an grime.
Now apply a paper thin corating on the cpu heat spreader. I repeat, paper thin. The only pupose of a thermal conductor is to fill up the air gaps in the conatc are of ur cpu heat spreader and the heat sink.Too much paste will make it act like an insulator. Or , the easiet way is to put a dab of the paste on the centre of the cpu and put the hsf on, as under pressure, the paste shall spread out. For visual reference refer imgaes on google. Loads of them.
I assume you are using the paste that do not need a curing time. Look on the side of your packet and lookout for the word "needs curing time" or something. If so then it needs a few hours of thermal activity to actually start performing to its optimal level.
Next ,hows the things inside the cabinet? Are wires and connectors hanging around? have you added a gfx card lately?
If so please look up on cable management and ensure proper air flow...
As some one suggested ensure that ur exhaust cabinet fan, fixed on the rear side of the cabinet is working.
And finally the EIST, ensure its turned on in Bios, Then in windows, use cpu-z utility to monitor CPu speed in MHZ...u shall see the CPu speed varying
And last of all, cpu temps depend on the ambient temps prevalent... Good luck!