Windows Issues please help!

[Nooblet]

Hey Guys im having a problem. I bought a new GFX card at the store so I took it home and put it in, it diddnt work. I called the company NVIDIA and they told me that my mother board diddnt have enough watts.
So I walked my happy **** down to the store again to buy a 500w power supply. I put it in and it was all in proper like, I double and tripple checked it.
Then I go to turn on my computer (just bought it in jan) and instead of booting it goes to a black screen that says at the very end DISK BOOT FAILURE INSERT SYSTEM DISK AND PRESS ENTER.
I was told a few different ways to solve this and none of them worked. First I pushed F8 when I was booting it. All it does is make a clicking sound. I also tried to put in Windows but it says that I do not have enought Cache or somthing.
Any help please? Thanks in advance!

 

[N3051M]

DISK BOOT FAILURE INSERT SYSTEM DISK AND PRESS ENTER.

refers to either:
-unbootable media in a drive (floppy, usb, cd/dvd etc) <-not usualy associated with this error but i throw it in nonetheless
- hdd failure to load/mbr corrupt

try doing a memtest to test your ram
since you've delt with hardware recently, reseat those things you've touched - ram, cards, etc...
try booting with a winxp cd?
tried a chkdsk /f?

 

[iss]

given you were installing a video card it is possible you knocked a cable or power supply lead loose. you should double check all your connections.