I'm having this heat issue of my cpu having an idle temperature of 45+ degree celsuis at idle so i tried to check it by removing the heatsink and found out that it isn't the usual form of thermal compound which was in liquid state. Have any of you guys experienced this, and if you did, how did you solved it?
No it should definitely NOT be in a powdered state. If it's powdered it won't fill the gaps between the cpu and your heatsink properly and as a result you'll get less thermal transfer and higher temperatures.
You should definitely replace the thermal paste. Get some rubbing alcohol and clean the heatsink and CPU before reapplying it. If you can get your hands on some arctic silver 5 that would be good too.
It should not be powder, but it will not be a runny liquid either. It should just be like a very thick paste.
However, it doesn't matter anymore now that you removed the heatsink. You need to replace the thermal paste now anyway. As stated above, use rubbing alcohol to clean both the CPU and the heatsink of all traces of the old thermal paste.
Arctic Silver 5 should be easy enough to find at your local BestBuy or RadioShack.