can oem disk perform a repair installation after sp1 update

In reading the tutorial for doing a repair installation of Vista I read that if SP1 had been installed that a "slipstream" disk with SP1 had to be used. Can you not use the OEM disk to do a repair and take it back to the original installation and then update to SP1. I don't want to lose any data that had previously been on the hard drive. I cannot get it to boot now with any of the options such as "start up repair" and Bootrec.exe.

NO.
"The Vista installation DVD that you use to do the repair (upgrade) install must be the same or newer version of Vista with the Windows Updates and SP level than what you currently have installed. If the DVD is a older version, then you cannot do a repair (upgrade) install with it."

If I was You I would just perform a re-install with your Disk.

Note- another way, is to use this partitioner to install Vista on another partition, log into the new install, retrieve your data and delete/re-install Vista after deleting BOTH Vista Partitions. You will essentially be dual booting, retrieving data from the bad Vista install, booting back into the Vista disk and deleting ALL partitions, then re-installing Vista again as a single install into the unpartitioned space.
Tutorial: http://www.vistax64.com/tutorials/163304-dual-boot-using-free-partitioning-software.html

Note-sometimes when you perform a boot (startup) repair, it has to be done twice.