The company said a backup of its domain name server (DNS) system late Tuesday night had caused corruption of some data, depriving customers of about 25 percent of the system, including Web and email access.
A representative said that regions had been individually brought back online since Tuesday, with full access restored late Thursday afternoon.
No estimate on the number of individual customers affected was available.
Excite@Home has been struggling with email and other outages for several months, most recently seeing customer complaints about sporadic availability of Excite Mail.
Spokeswoman Alison Bowman said the current problem was unrelated, however.