Most of the solutions you see are valid for the retail version, digital distributions, or the old EA client (EADM). The new EA client (Origins) uses a different installation process, that's why you can't find the DA Updater Service (services.msc)
This is the solution you are searching for:
http://answers.ea.com/t5/Dragon-Age-Origins/Big-troubles-with-Dragon-Age-Origins-Ultimate-Edition-Origin/m-p/4231926#M10187
or
http://answers.ea.com/t5/Dragon-Age-Origins/How-to-fix-some-DLC-issues/m-p/1640139#M4167
- - -
Follow the instructions from the Dragon Age Wikia ("Manual installation"). You'll have to download the required DLC files and install them with the Dragon Age Content Updater Tool (Dragon Age\bin_ship\daupdater.exe).
Ultimate Edition DLC List - campaigns:
- Witch Hunt: DAO_PRC_STR_1.1.dazip
- Witch Hunt Offer: DAO_PRC_STR_O_1.0.dazip
- The Darkspawn Chronicles: DAO_PRC_DRK_1.0.dazip
- The Darkspawn Chronicles Offer: DAO_PRC_DRK_O_1.0.dazip
- The Golems of Amgarrak: DAO_PRC_GIB_1.0.dazip
- The Golems of Amgarrak Offer: DAO_PRC_GIB_O_1.0.dazip
- Leliana's Song: DAO_PRC_LEL_1.0.dazip
- Leliana's Song Offer: DAO_PRC_LEL_O_1.0.dazip
Ultimate Edition DLC List - extra items*/quests**/add-ons*** that will be added to the main game and dlc campaigns):
- ***Return to Ostagar : DAO_PRC_CP_1_1.1.dazip
- Return to Ostagar Offer: DAO_PRC_OCP_1_1.1.dazip
- ***Warden's Keep: DAO_PRC_NRX_1_1.0.dazip
- Warden's Keep Offer: DAO_PRC_ONRX_1_1.0.dazip
- ***The Stone Prisoner: DAO_PRC_CP_2_1.0.dazip
- The Stone Prisoner Offer: DAO_PRC_OCP_2_1.0.dazip
- *Feastday Gifts: DAO_PRC_CP_3_1.0.dazip
- Feastday Gifts Offer: DAO_PRC_OCP_3_1.0.dazip
- *Feastday Pranks: DAO_PRC_CP_7_1.0.dazip
- Feastday Gifts Offer: DAO_PRC_OCP_7_1.0.dazip
- *Witchcraft (for Origins): DAO_PRC_STR_DAO_1.0.dazip
- *Witchcraft (for Awakening): DAO_PRC_STR_EP1_1.0.dazip
- **Golem's Might (for Origins): DAO_PRC_GIB_DAO_1.0.dazip
- **Golem's Might (for Awakening): DAO_PRC_GIB_EP1_1.0.dazip
- *Blightblood (for Origins): DAO_PRC_DRK_DAO_1.0.dazip
- *Blightblood (for Awakening): DAO_PRC_DRK_EP1_1.0.dazip
- *Battledress of the Provocateur (for Origins): DAO_PRC_LEL_DAO_1.0.dazip
- *Battledress of the Provocateur (for Awakening): DAO_PRC_LEL_EP1_1.0.dazip
- *Blood Dragon Armor: DAO_PRC_PROMO_ME_1.1.dazip
Note - Offers: They are required for the DLCs to start off properly.
Note - Feastday: Feastday Gifts and Feastday Pranks are available in a combo pack named Feastday Combo Pack. If you have one you don't need the other.
