I had a thought...
If you have integrated graphics then you are losing a substantial portion of your 4GB for use as video memory. What we really need at this time are:
1) CPU type, and clock speed if possible
2) GPU type (integrated or plug-in card, amount of video ram)
3) O.S. version and "bit size" (32 or 64 bit)
Also, if you have both versions (64/32) of Java chances are you are running 32-bit as it seems to be the default. If you even have 32-bit Java installed the website won't even give you the option for 64-bit but will update the 32-bit. If you had 32-bit when you installed Minecraft then there are some configs that have to be changed to load 64-bit.
I found it easier to completely delete all traces of Minecraft and launchers, then do the same for Java. Then I loaded the latest version of 64-bit Java and re-installed Minecraft/FtB.