The Nasdaq composite index gained 29.49 to close at 3,529.07, and the Standard & Poor's 500 index climbed 13.15 to 1,420.96.
At the end of regular trading, Intel was down 56 cents at $115, and Microsoft inched up 94 cents to $68.81.
While a judge considers a government proposal to split Microsoft, the software juggernaut will unveil June 1 its strategy to further integrate the Windows operating systems with the Internet. The plans could more closely tie the company's applications and operating systems, a central issue in the landmark antitrust case.
The CNET tech index climbed 37.17 to 2,799.66. Gainers surpassed decliners, with 62 of the 99 stocks in the index rising and 37 falling.
Of the 18 sectors tracked, server hardware companies posted the strongest gains, rising about 6 percent. Internet services companies were the day's biggest losers, although they slipped a mere 0.73 percent.
Among members of the CNET tech index, Dell and Citrix Systems posted strong gains.
Dell rose $5.19, or 11 percent, to $49.88 on a volume of 61.4 million shares, almost double its average daily volume, which made it the most actively traded company on the Nasdaq Stock Market. It released surprisingly strong earnings after the markets closed yesterday.
Citrix rose $4.72, or 10 percent, to $52.47 after an analyst at Lehman raised earnings estimates for the company.
Among the decliners, Cypress Semiconductor fell $3.13 to $48.88, Intuit dropped $1.56 to $28.50, and Nextel Communications lost $5.44 to $92.38.
The Philadelphia semiconductor index gained 16.37 to 982.15, led by chip equipment maker Teradyne, which rose $4.25 to $87.25.
Network equipment giant Cisco Systems today said it has agreed to acquire Sweden's Qeyton Systems, a maker of optical networking equipment, in a stock deal valued at $800 million. Cisco dropped 31 cents to $59.94.
Vodafone gained 94 cents to $42.06, while Bell Atlantic fell $1.78 to $52.94. Verizon Wireless, the mobile phone giant created by the two companies, lost voice mail messages, apparently without backups in place, in a glitch that has affected about 16,000 customers in Minneapolis.