Windows 7 - Monitor doesn't come on after turning computer on, sometimes.

Hi, i recently upgraded from Windows XP to Windows 7 Ultimate. I have experienced a number of problems, and have muddled my way through most of them, except for this one. Sometimes, and this is completely at random, when i turn on the computer, i get no picture, but i can hear sounds coming out of my speakers. However, if i boot into safe mode, it comes on every time. It is notorious for doing this when i install updates, and I have not been successful at installing updates yet. I am ready to go back to XP, but may consider staying if i get all the bugs worked out. Here's what i've done so far:
1. Updated Graphics Card Drivers.
2. Under Power Options, Set turn off monitor to never.
3. Changed S3 to S1 in Bios (this corrected the sleep issue i was having, apparently common)
4. Booted into Safe Mode, Under Device Manager, Changed settings for USB Root Hubs to allow them to stay on.
Have tried all of this, and still nothing. I know for sure the graphics card is fine, and i am using the most up to date drivers for my card. Here are the specs for my system, maybe this will help:
Dell Dimension 5100C
3.0Ghz Intel Pentium 4 processor
2.0 GB of Ram
80gb hdd
ATI Radeon X600 Series graphics card; 128mb
Windows 7 is the 32 bit version. Thanks for any and all help.

2 Things come to mind... 1 is that you wouldnt have to quote your system specs in a post if you filled them in on your profile. AND...

Your video card is at the very bottom of the compatibility for Windows 7, 128MB video memory is a very low amount for today's PC's. Make sure you have all Windows 7 advanced video tweaks (Aero, etc.) turned off.

Some of the post involving your video:
Win 7 graphics drivers for Gateway MX7525

ATI MOBILITY RADEON X600 and Aero

ATI mobility raedon x600 aero effects help

OK, i already ruled out the graphics card, but i guess it could be time to upgrade it. The computer runs fine, it just does this. It even comes in and out of sleep ok. Will do some more digging around other forums and Microsoft's website to try and find a solution, unless you all have any more. Thanks.