Less than two weeks after announcing its fall 2006 prime-time schedule to advertisers at its upfront presentation in New York, NBC is adjusting its lineup with major revisions on five nights and a retreat from its strategy of launching new shows in the 9 p.m. (ET) hour.

One of the most high-profile moves is a shift for the Warner Bros. Television Studios industry drama “Studio 60 on the Sunset Strip,” which originally was scheduled for Thursdays at 9 p.m. The network is moving the show to Mondays at 10 p.m., replacing psychic drama “Medium,” which is being held for Sundays at 10 p.m. after NFL Football completes its run in January.

That moves “Studio 60” out of what was becoming a very competitive Thursday night. ABC announced at its upfront presentation last week it is moving one of its strongest performers, the Sunday medical drama “Grey’s Anatomy,” to Thursdays at 9 p.m., where CBS’s forensic drama “CSI” already dominates the time period. Now NBC is scheduling that time slot with its game show “Deal or No Deal,” which was a surprise midseason hit for the network.

“We are countering the ‘Grey’s’/’CSI’ combo,” said Kevin Reilly, president of NBC Entertainment, during a conference call with reporters Thursday. “It is a genuine alternative to the very tough drama competition.”

NBC’s revised fall schedule:

Monday

8 p.m. “Deal or No Deal”

9 p.m. “Heroes”

10 p.m. “Studio 60 on the Sunset Strip” (new day and time)

Tuesday

8 p.m. “Friday Night Lights”

9 p.m. “Law & Order: Criminal Intent” (new day and time)

10 p.m. “Law & Order: SVU”

Wednesday

8 p.m. “20 Good Years” (new time)

8:30 p.m. “30 Rock” (new time)

9 p.m. “The Biggest Loser” (new time)

10 p.m. “Kidnapped” (new day and time)

Thursday

8 p.m. “My Name Is Earl”

8:30 p.m. “The Office”

9 p.m. “Deal or No Deal” (new day and time)

10 p.m. “ER” (“The Black Donnellys” in January 2007)

Friday

8 p.m. “Crossing Jordan” (new day and time)

9 p.m. “Las Vegas”

10 p.m. “Law & Order” (new day)

Saturday

8 p.m. “Dateline Saturday”

9 p.m. Drama Series Encores

Sunday

7 p.m. “Football Night in America”

8 p.m. “Sunday Night Football”

Because of the introduction of two new dramas on Mondays, NBC moved new thriller drama “Kidnapped” off Tuesdays to create a two-hour “Law & Order” franchise block. That allows NBC to focus only on one new Tuesday drama, the 8 p.m. football series “Friday Night Lights.” “Kidnapped” is moving to Wednesday at 10 p.m., pushing the night’s veteran performer “Law & Order” to Fridays.

“Law & Order” isn’t the only Friday change. The procedural “Crossing Jordan,” which was being held for midseason, will start off the night at 8 p.m.

On Wednesdays, NBC is moving reality series “The Biggest Loser” out of the 8 p.m. hour, where there is multiple reality competition on other networks, into the 9 p.m. hour, which has been dominated by ABC’s drama “Lost.” NBC’s two new comedies will move to the 8 p.m. block.

NBC has traditionally has been the first network to announce its schedule during the upfront presentation week, which served the network well when it was No. 1 in adults 18 to 49 but has left it at a competitive disadvantage now that it is ranked No. 4 in the advertiser-friendly demo.

“Adjustments are always made,” Mr. Reilly said, noting that NBC is “discussing” changing up its announcement date for next year’s upfronts. “We are normally in the dark by going first.”