OK finally figure it out. Can't believe the CVI guys, that wrote the compiler, don't know this but the issue was with defines that are entered under the Configuration Options. Under 'Options\Build Options\Compiler Defines'. In 2009 one entered multiple defines seperated with a comma then a space, but in CVI 2010 the seperation was ONLY with a space. So in my 2009 project I had defines as "/DWIN32_LEAND_AND_MEAN, /DMY_DEFINE". Thusly the 2010 compiler was complaining that the ',' was the first character in each .c file. Taking out the ',' as in "/DWIN32_LEAND_AND_MEAN /DMY_DEFINE" fixed everthing.
Glad I didn't 'make a new project and add the files in one by one'. That would have been another day or two, fiddeling with libs, instrument files, project settings and etc.