Why can't i play minecraft anymore?

Everytime i play it crashes when i join a server or whenm i go on a multiplayer

Minecraft Random Lag Spikes? - 1

I've had minecraft for a while and recently when i try and run a game it starts to bring on random lagspikes, and i have optifine, but this comes with every single server i'm on so its not server lag, and i have about a 54 ping, so is there anything you can recommend for me to get me back into the 60+ fps i used to get on my desktop. I don't have too much of a good desktop at the moment but it used to run fine, heres my specifications:
Operating System
Windows 7 Ultimate 64-bit SP1
CPU
Intel Core 2 Duo E4300 @ 1.80GHz69
Conroe 65nm Technology
RAM
8.00GB Dual-Channel DDR2 @ 333MHz (5-5-5-15)
Motherboard
Hewlett-Packard 0A68h (XU1 PROCESSOR)72
Graphics
HP x20LED (1600x900@60Hz)
256MB NVIDIA Quadro FX 380 (NVIDIA)47
Storage
931GB Seagate ST1000DM003-1ER162 ATA Device (SATA)30
Optical Drives
HL-DT-ST RW/DVD GCC-4482B ATA Device
Audio
High Definition Audio Device

Minecraft gets disconnected frequently?

My computer frequently gets disconnected after just 1-10 minutes of playing on a server. The connection drops for just a few seconds but I'm kicked from the server. Why does this happen? My brother s computer is on the same network and never gets disconnected, and this only happens to me on Minecraft.

Is it possible to install a Dynamic map on my standard minecraft server?

Is it possible to install a Dynamic map on my standard minecraft server? - 1

Added (1). I assume its only on bukkit or spigot servers but i don't want those because they unload the spawn chunks

How to fix the error on minecraft failed to connect the server connection timed out: connect?

So i recently got a new computer and it hasn't been the greatest. Its slow and when i play minecraft all it says is that and like sometimes i can get on the server but like 2 mins on it says that msg. Its driving me crazy cux i wanna play minecraft.

My Minecraft player is randomly exploding?

So in Minecraft my player is just randomly exploding. I'm in 1.8 and it used to be just 6-8 blocks but now I'm getting explosions up to 800 blocks. Somebody help? I'm not being greifed I'm alone in a server with just me and my friends. Somebody help! It destroyed 2 buildings!

How to use a desktop as an offline server for minecraft so you re not using your internet data?

How to use a desktop as an offline server for minecraft so you re not using your internet data?

How to host my own Minecraft server?

Alright, so a friend and I want to host a simple minecraft server. We really just want it to be completely Vanilla, and only a few commands (/tpa [username] and /back) and the admins to be able to go from creative mode to survival and such. The problem is, we don't understand much of how the whole hosting works. What do we have to do for a server like this, and what place would you suggest us to buy a server if this is what it used for? Sorry if this is really noob-ish, but I really don't understand this stuff!

How to create a server in minecraft without buying the game?

How to create a server in minecraft without buying the game? - 1

Getting stuck in multiverse portals Minecraft?

Whenever I walk into a multiverse portal, it teleports me to the other world, I can walk out of the other portal connected to that portal, but then it teleports me back, the only way to get out of this endless loop is to /mv tp world in the console, I will open my server to the public and can't have this happening to everyone who joins the server.