Graphics Card Driver Problems

[Edonnel]

Okay, I know I should've made more research into this, but here it is. I currently have a VERY OLD graphics card and wanted to upgrade to a new one. The old one didn't require any power cable (is an AGP) and was running great for normal applications. It is a NVIDIA Geforce4 MX 420 (yeah, that bad) I wanted a little boost in performance so I bought an ATI VisionTek Radeon HD3450 512 MB AGP 8x Graphics Card 900374 from Amazon. After the package came in, I knew to uninstall the old NVIDIA driver and then shut the computer. I then took out the old card, put in the new, plugged everything back in, and turned on the computer. Then the computer screen beeped and read something like: PLEASE CONNECT POWER CABLE TO CARD. REFER TO THE GETTING STARTED GUIDE. I read that I need an extra power cord to power the new card! I decided to take out the new card and put the old back in and text a computer friend about how I can power it.

BUT! My main problem now is that when I boot in Safe Mode, the screen has a VERY LOW resolution and stripes of black running down where some particles of colors appear and the mouse and desktop are hidden behind! I tried to restore my computer to RIGHT before I uninstalled the drivers, but absolutely nothing changed when I rebooted into Safe Mode again. I then went online to download the latest drivers online and installed them "successfully" but yet again, after restart, no change. I dug into my CDs and found the computer's correct driver for the graphics, installed it... No change. PLEASE please help! All I want to do is run my computer's old graphics card until I figure how to deal with the new one, but it is very difficult to see the screen at a low resolution and thick black bars running down the monitor! Now, I DO have an overclocking program called RivaTuner than works, so do I need to uninstall that first?
Here are ALL the specs:
Original Card (Old): NVIDIA Geforce4 MX 420 64 MB (AGP)
New Card: ATI VisionTek Radeon HD3450 512 MB AGP 8x 900374 (not sure what the last #s mean)
Computer Specs: Dell Dimension 4550, Pentium 4, 32-bit, Single Core (don't laugh), Windows XP Home

I think that's all so please try to help me out!

[Edonnel]

Fixed! Wow, I feel stupid... I just logged on NOT in safe mode and the drivers installed themselves. No glitches or anything. Now I have to figure out how to use the new card!

[SauceBoss]

the 3450 is not a strong card but it sure is an upgrade from your old one, im also glad you found the problem and updated us here with solution
enjoy your new card.

[mazasrb]

My previous was little better NVIDIA Geforce4 MX 440 SE,But for it's age it's good gfx