Starts in Safe Not in Normal

What's the difference between Safe Boot and Normal?
I used sysconfig to turn off everything that wasn't running in Safe. Normal (selective) boot still bombs.
Context:
Computer is a used Optiplex. Came with Xp. I added w7 home premium 32 [a year ago] and w7 home premium 64 this summer. Been Stable in '64 for two months. That's 3 partitions total.
Subsequent to an acronis restore that failed, my W7 boots have been problematic. Xp works fine. But both w7 partitions will launch in Safe but yeild a blue red or green screen on "normal boot". Soon as I key in the password. I always assumed that some of the "Apperance" items in W7 drove my video card nuts. As soon as I used Norton 16 adjusted for "best performance" [ makes it look like classic windows with a square start box ] the problem went away.

Current strategy: Disable everything I can till it starts and then add services back in till I find the culprit.
Prior posts on "boots safe but" topic contain warnings as to age[1700 days..]. I've done system repair, boot fixes from neosmart, spotmau, and the partition activator. Since the data is "there" I believe this is a video conflict.

So if anyone knows how to do Selective Startup with only Safe Mode Components...I would like to know.
Could be I need a wiped disk and a scratch install, starting with W7 and adding the xp partition later.
Apologies if this post is in the wrong place.
-wbajr tbc

Thanks for the replies and the resources. The Question I asked ( compare Safe with Normal ) was a bit silly but honest. If I don't get a flashing screen in safe, why can't I disable all but "safe" services and then add back? Well the resources have exposed me to a lot that I don't know. The difference Acronis makes between "Logical" and "Primary" on bringing back a partition. Why 3 partitions? I was developing Excel Macros at home as Work transitioned from "NT" to System 7 and from Excel XP to Excel 10. The 64 bit W7 was added "just to see if it would run " on the ol'e Optiplex. [ 4 gig of memory and room for more]. System Restore is out of the question because the disk has been wiped. My primary Pc is a Lenovo Lap top..so the Optiplex is used primarily for the large monitor attached when dealing with VBA and Spreadsheet at the same time. Will try a few more things and then a "Scratch Install" [ getting efficient at Scratch...].
Again: thanks for all the leads and resources.
-wbajr tbc
If I come up with a solution before Scratch: I'll post what it was and perhaps save some one some time.

Footnote: The Solution was a new computer [Optiplex 755 replaces Optiplex 745] There were 2 issues: Bad Mother Board and Failure to Read. None of the Dell Diagnostics picked up the MB problem. ( 3 bad caps ) The system was stable enough to Boot Safe. That's all. Refreshing the drive with Acronis validated images could not solve the problem. Symptom: System would shut down but never do a shut down - restart cycle. The screen would go black, the fan took off and punch button force quit was the only recourse. In the new environment, the restored drive would still only "safe boot". Reading the instructions for Acronis Universal Restore brought instant relief. On the new computer: Windows disk repair, Spotmau, and even EZ Re could not get the restored image to work. (no slight on the makers of EZ Re, I'm not sophisticated enough to use any of the tools other than "automatic repair". In the "new environment": Acronis Squawked till I could get "On line" Windows Activated On Line: Office 10 did not. That took Phone activation but was otherwise painless.
Again: Thanks for all the Leads
-wbajr tbc