Hi Lawrence,

The  Kingston RAM seems to be have the right specifications and should be compatible with the Vostro 200. However, the Radeon HD 7750 requires a power supply of 400 W and above and the Vostro 200 systems either come with a 250 W or a 300 W power supply which may cause issue with proper functioning of the video card.

I would advise to click on the Dell parts and upgrades link mentioned below, to check upgrade options and compatibility of the video card and the memory.

http://dell.to/QFAzlQ

Please reply for any further questions.

Hi Lawrence,

Sometimes the video card may run on a less power supply than required. However, certain functionality issues may occur because of it.

I have checked the system requirements for the Sapphire Radeon HD 7750 and it states it requires 400 W. You can check the link below.

http://bit.ly/T0yuPH

Please reply for any further help.

But the hd 7750 only requires 218 Watt maximum in the review on pcper.com.

7750 review:www.pcper.com/.../Overclocking-Power-Consumpt

Thanks for the suggestion Abhishek, so would you suggest me buying the  AMD Radeon™ HD 6450 ? Or which? Please there's only 2 listed in the dell recommended section.

Forget about the HD 6450 or the other on the list.  The HD 7750 is what you want to play today's games.  Others have used the HD 7750 on their 300 watt units.  It only uses 50 watts under load, so I don't see that you will have an issue.  All I can say is that I would do it and not think twice about it if you have the mini tower.  

You have 4 slots for memory.  If you have two 512's now @ 667mhz and keep them in, your Kingston 800mhz will default to the slower speed.  However, I would say that 3 GB's @ 667mhz is probably better than 2 GB's @ 800mhz if you pulled the 512's out.  

Kelbear1 is correct ... the HD 7750 will run fine ... both the video card and memory you picked out should run fine.  the HD 6450 is a terrible quality card.  newegg has your video card for $10 cheaper than tigerdirect: www.newegg.com/.../Product.aspx

I don't understand what you mean by if I have two 512's now @667mhz and keep them in Kelbear1 can you suggest me a brand of Ram that works for my computer? I searched up for the kingston 800mhz because on the dell upgrade replacement site accessories.us.dell.com/.../productdetail.aspx it's 800mhz so I search up for 800mhz ram.

Please link me the specific kind of ram that works for my computer thank you

The 800mhz speed will work fine.  It is just that if you mix 800mhz and 667mhz, it will simply default to the lower speed.  Not really a big deal, but just don't expect the faster ram to run at its rated speed if you use them with the 667mhz ram that you have now.  The difference would not be noticed anyway.  

I see, but how do you know I have 667mhz or 800mhz? so should I get 2 667mhz? Because I already have 2 Ram card inside my desktop right now and 2 slot left

I only went by the specifications that you linked for your system.  It showed 2 512's at 667mhz.  Just download and run CPUZ HERE.  It will show you what you have. It really does not matter what you get if they cost the same which they probably do.  At the same price, you might as well get the 800mhz because you may down the road take it up to your max which is 4GB by pulling out the 512's and adding another 2 GBs.  This way you'll have the faster speed.  I will say though that I would be more comfortable with Crucial ram HERE than Kingston Value ram.  

Sorry I just found out that my computer is the Slim verison of vostro 200, so it only support 250W. AM I still able to support the Sapphire 7750 HD? Also Kelbear the Crucial ram doesn't say how many Mhz but it does fit my computer because of it fits PC2-5300! Please reply thank you!

You will only be able to use a low profile card now with the slim version like this one HERE.  Will it work with your 250W PSU?  It might.  If you want to upgrade the PSU, get one of these HERE. 

I'm not sure what you mean by the memory.  It shows both PC2-5300 (667mhz) and PC2-6400 (800mhz) being compatible HERE. 

Well on http://support.dell.com/support/edocs/systems/vos200/en/slim_tower/om_en/pdf/PK009A01.pdf it saidsthat 

Your Dell™ computer provides the following slots for PCI and PCI Express cards:
• One PCI Express x16 card slot (SLOT1)
• One PCI Express x1 card slot (SLOT2)
• Two PCI card slots (SLOT3, SLOT4)

Can you confirm if I can use the Sapphire 7750 HD Express http://www.newegg.com/Product/Product.aspx?Item=N82E16814102969&nm_mc=KNC-GoogleAdwords&cm_mmc=KNC-GoogleAdwords-_-pla-_-NA-_-NA

It's cheaper than the other one and matches my budget.

• One PCI Express x16 card slot (SLOT1)

This is the one you want.

You cannot use that card.  It is not a low profile video card and will not fit in the slim case.  You can only use the one I linked.