the original description even 32 bit win8 is going to bug the shit out of it, if you open chrome with 2 tabs it will most likely shut down due to reaching 100% ram usage, the celeron one might be able to handle it but then again its celeron cpu
Certainly, muhammad, 4 GB of RAM will make a very noticeable difference, even with your current OS. But 32bit OSes cannot use quite all of 4GB. 64bit Windows 7 at least, makes better use of available memory because of an improved memory manager, plus is capable of using all of that 4GB compared with 32bit W7.
W8.1... I don't know how efficient its memory management is. Of course, there are still softwares that are not available in 64 bit, but 64 bit Windows 7 or 8 will run them as 32 bit. So consider a 64bit OS; your current E4500 is capable of running it.