Help Phone hang issue

[ravi224]

hi,
m using htc sensation 4g and i am facing one problem. When i use my phone for 1 day(use internet and play games etc.) my phone becomes very slow, everything just hangs,even contacts, messages load very slowly and if i restart it than it becomes normal after around 30 mins. Its really frustrating for me....please help me on this.

 

[saywat?]

do a factory reset if that doesnt help reinstall the OS

 

[ravi224]

well i havn't upgraded my OS, its the same OS which has been pre-installed by HTC. Do i still need to reinstall it?