WIN 7 startup problem

1. Win 7, Home Premium, Pentium dual core, E5300 2.6 GHz
2. PC crashed...no safe mode start; no DSRM start; no start De-bugging mode.
3. used Repair Disk to start-up; no repair worked.
4. used Recovery Disk to re-install OS.
5. appears to be starting...up to log-in screen
6. put in p/w and enter..shuts down
7. cycle repeats.
8. yes, starts in Safe Mode
9. tried all the usual elimination of Services and/or Start-up items
10. cycle repeats - but,
11. starting in Directory Service Repair Mode (DSRM) full functionality appears.
12. Tried restore from past known "Good" date - same cycle again
13. ran sfc/scannow...nothing
14. Tried restore from backup "SyncBack"
15. all data comes back but start-up cycle remains

What do I do next?

Hello ldickens and welcome to Seven Forums.

It looks like you've tried the usual software troubleshooting. Perhaps you have a hardware issue (failing motherboard, hard drive, etc.) One of the Forum experts prepared this troubleshooting tutorial which includes various hardware tests in the first "Information" box. I'd start with them. If hardware checks out OK I'd try one more time with the actual troubleshooting steps in the order listed. Follow the steps exactly and don't skip any steps just because you might have tried it previously.

Troubleshooting Windows 7 Failure to Boot

Check the hard drive with the manufacturer's diagnostic tools.
Hard Drive Diagnostics Tools and Utilities (Storage) - TACKtech Corp.
Hard Drive Diagnostic Procedure

Thanks marsmimar & theog for your timely responses. I think it unlikely to be a hardware problem as it loads and operates well DSRM. But tomorrow I will be pursuing "Troubleshooting Windows 7 Failure to Boot" step by step. Thanks for your help.
Larry D