I am running BOINC Manager 6.4.7 under Vista x64, Service Pack 1 (6.0.6000.16386) but all my projects show my computer as having:

'Microsoft Windows XP Professional x64 Editon, Service Pack 2, (05.01.2600.00)'

Previously, I had been running BOINC on an XP Pro x86, Service Pack 3 machine before installing it on this Vista machine. It was not upgraded, a totally new install.

In searching the boards, I did not find anything about this occurring.

TIA!

Did you make a copy of the old BOINC installation and then paste this onto the new windows?
If so, then this is where your projects are getting the "XP" info from; it's in one of the files.

No, I didn't. I didn't backup any BOINC files from my previous XP install.

I am running BOINC Manager 6.4.7 under Vista x64, Service Pack 1 (6.0.6000.16386) but all my projects show my computer as having:
'Microsoft Windows XP Professional x64 Editon, Service Pack 2, (05.01.2600.00)'
Previously, I had been running BOINC on an XP Pro x86, Service Pack 3 machine before installing it on this Vista machine. It was not upgraded, a totally new install.
In searching the boards, I did not find anything about this occurring.
TIA!

Starting BOINC messages (at "Messages" tab of BOINC Manager) contains both "OS:" and "Computer ID:" with info about your present computer. There is written "Vista"?

BTW, You can try to look at your present computer directly with address (this one is for SETI@Home project) "http://setiathome.berkeley.edu/show_host_detail.php?hostid=" where You should add number from Your line "Computer ID:"

All this situation looks like here is another account. In that case You can read The BOINC FAQ Service, section "10. Account Trouble", topic "Two accounts, how to get everything synchronized?" and "Can I merge accounts?" from the first section.
___________
WBW, Leonid