2 beeps indicates a RAM issue with your Mobo. Have you tried using one stick of RAM?
Did you bench test before assembling in the case and did it result in any issues?
Note: 750W, with a good quality PSU, is the minimum recommendation for the Sapphire R9 290 GPU so that should be addressed asap.

 

Here are the beep codes for MSI motherboards.

What do the BIOS 'beeps' and codes mean? | MSI HQ User-to-User FAQ

Two beeps may indicate a bad RAM stick or improper configuration. Remove all but one stick of RAM and see if the system will boot. If it doesn't then try another stick. If you have changed BIOS settings to overclock RAM already try clearing the CMOS according to your motherboard manual's instructions.

 

I have tried using only one stick of RAM, and tried both the sticks of RAM in different configurations too but still nothing. I have cleared CMOS too and nothing. I didn't do an external build first (although now regretting it) before building in the case so no I haven't bench tested it, I'll do that now and post the results in a bit.

 

I removed the graphics card and it worked, the display came on asking me for boot media (but I still had 2 beeps?). Does this mean my graphics card is faulty?

 

Since the video card also has ram in it it is possible you found the problem. I have seen several new Msi boards that give one beep when it first starts and then another beep nefore the OS actually boots so I think you need to replace the video card. Now it also still could be the psu as well since the requirement to use the card is much greater than not and your psu is poor quality and not enough for that video card with the rest of the system. Do you have any other ram to try as I find that Corsair ram has way too many compatibility issues these days. The Psu needs replacement anyway with a better quality higher wattage such as XfX or Seasonic so I would replace that then try the video card and if still no then replace the video card. BTW are you certain you have the psu plugged into the video card and the right connections?

 

Thanks for the reply, I tried the only other RAM I had which was the Kingston 1GB RAM from my old computer but it must be so outdated that I couldn't fit it in (because the notches didn't match up). As for the PSU plugged into the video card, I connected the two PCI-E connectors into the slots into the graphics card from the PSU, this is correct? I checked all the other connections and they seem to be in properly. I guess I should buy a better PSU and see if that works, otherwise get a replacement graphics card. Should I buy some different RAM to see if it is a compatibility issue?

 

The first place I go to check for compatible RAM is the QVL for the motherboard as these are the sticks that have been tested on the motherboard. The second place to go is to the RAM manufacturer's website, where you look up the model number of the motherboard.

If you choose to replace your RAM, G-Skill is widely recommended here.

G.SKILL - RAM Configurator

 

I agree on GSkill but it gets easier if you use Crucial which is also Micron ram except that Crucial guarantees the match if you use the configurator on their site at:
Crucial.com - DRAM, solid state drive (SSD) memory upgrades for Dell, Mac, Apple, HP, Compaq, Lenovo, Acer, ASUS
I also agree with MPR and have learned the hard way if the exact model is not listed on the motherboard mfgr site as tested and approved ram, I don't buy it.

 

I have just finished my first build but when I turn it on, the display is blank and the motherboard makes two beeps. I have checked that the RAM is seated properly and the problem persists. The screen on the mobo ( Debug?) comes up with a2 and then stays at around 40.

A2 indicates a normal check of the drives, I cant find what the 40 indicates, but it might tell you in the manual for that board.

 

Good quality Mobo's and good quality RAM rarely have issues. You definitely need to replace the PSU with a good quality sufficiently powered unit before reinstalling the R9 290. SeaSonic-XFX-Antec HCG are top quality.
"If" the Corsair RAM is an issue, I'd go with G.Skill.