Dell ( DELL) got downgraded Friday by JPMorgan, which said it believes the PC maker won't reap outsize rewards from this year's rollout of Microsoft's ( MSFT) Vista operating system.

JPMorgan cut Dell to underweight from neutral, citing margin pressure and tough competition in the corporate PC market. Shares fell 2% early Friday.

Dell shares dropped 17% last year as the company struggled with accounting problems and ceded market share to Hewlett-Packard ( HPQ). But the stock, along with much of the rest of the technology sector, has rebounded this year, gaining nearly 5% in trading since the New Year.

On Friday, shares dropped 49 cents to $25.75.