Trying to install XFX R6770 core edition on Dell E521

Ok....I tried this new graphics card on my Emachines comp but that particular comp has integrated graphics that nobody on earth seems to know how to disable....and we have tried everything since July 12! So I decided to upgrade my older Dell E521 and insert the card there....but OF COURSE im just having more issues. He uses a Sanyo 26" flat panel tv as a monitor but when I hooked it up with a HDMI from the card to tv I got the same message that I did with the emachines comp saying no signal. The cards fan is working well...I have the card plugged into the power source. The disc will not load the drivers...says to go to find the latest driver. But I don't find anything other than an amd catalyst thing..im assuming thats what i need considering how long and hard I looked. I will post what Dell said the specs were...wasn't sure what everyone would want so I just copied and pasted. Note--I upgraded the power supply to a Thermaltake 600W..I had issues with the Dell and the hard drive died so I just upgraded it to a new hard drive Western 1Tb.......at the same time I had to wipe the whole thing out and do a new install of the OS taking it from a Windows Vista 32 bit to Windows 7 32 bit Home Premium edition. I added some memory as well and it now has 4GB loaded. I know a lot of people will probably tell me to update the processor but after the surprise hard drive need and the new power supply etc...this girl is tapped! Anywayyy......here were the former specs on the Dell (Btw, while the card does fit the comp, it did not fit the case. It was about 1/4 an inch to far past the last remaining slot so I hillbilly modified the case with some tin snips...lol...whatever works I say! And it did but I have yet to get the actual card running!)

Processor---Processor type AMD Athlon™ 64 X2 dual-core processor
AMD Athlon 64 processor
AMD Sempron™ processor
Level 2 (L2) cache Up to 1 MB per core
Up to 256 KB for Sempron processors

Memory---Type 533-MHz, 667-MHz, 800-MHz (when available) DDR2 SDRAM
Memory connectors four
Memory capacities 256 MB, 512 MB, or 1 GB non-ECC
Maximum memory- 4 GB
NOTE: See Addressing Memory With 4-GB
Configurations to verify the amount of memory
available to the operating system.

Computer Information---Chipset Nvidia GeForce 6150LE
RAID Support RAID 1 (Mirroring)
DMA channels is eight
Interrupt levels 24
BIOS chip (NVRAM) 4 Mb
NIC Integrated network interface capable of 10/100 communication

Video Type--- Nvidia integrated video (DirectX 9.0 Shader Model 3.0
Graphics Processing Unit) or optional PCI Express x16 graphics card

Audio Type--- Sigmatel 9227 CODEC (7.1 Channel audio)

Expansion Bus--- Bus type PCI 2.3
PCI Express 1.0A
SATA 1.0 and 2.0
USB 2.0

Bus speed--- 133 MB/s
PCI Express: x1 slot bidirectional speed - 500 MB/s
x16 slot bidirectional speed - 8 GB/s
SATA: 1.5 Gbps and 3.0 Gbps
USB: 480 Mbps high speed, 12 Mbps full speed, 1.2 Mbps low speed

PCI connectors--- 2 connector size 124 pins
connector data width (maximum) 32 bits
PCI Express connector one x1 connector size 36 pins
connector data width (maximum) 1 PCI Express lane
PCI Express connector one x16
connector size 164 pins
connector data width (maximum) 16 PCI Express lanes

Drives---Externally accessible:
Bays one 3.5-inch drive bay (FlexBay) two 5.25-inch drive bays
Available devices Serial ATA drives (4), floppy drive, USB memory devices, CD/DVD drive, and Media Card Reader
Internally accessible: two bays for 1-inch high serial ATA hard drives

Connectors---External connectors: Video 15-hole connector
Network adapter RJ-45 connector
USB two front-panel and four back-panel USB 2.0- compliant connectors
Audio six connectors for 7.1 support
System board connectors: Serial ATA four 7-pin connectors
Internal USB device one 10-pin connector (supports two USB ports)
Floppy drive one 34-pin connector
Fan one 5-pin connectors
PCI 2.3 two 124-pin connectors
PCI Express x1 one 36-pin connector
PCI Express x16 one 164-pin connector
Front panel one 40-pin connector
Processor one 940-pin connector
Memory four 240-pin connectors
Power 12V one 4-pin connector
Power one 24-pin connector