Between two million and three million of 100 million hard disk drives manufactured by Fujitsu between September 2000 and September 2001 may have start-up problems when used in a hot and high-humidity environment.
Faults were found in the hard disks' controller LSI (large-scale integration) chips, supplied by a third-party vendor.
Fujitsu would not disclose the names of PC makers that purchased its drives, although it has been replacing faulty drives returned by PC makers, a Fujitsu spokesman said.
NEC used about 180,000 Fujitsu drives that could be affected, NEC said. Around a third of those have already been recalled. Most of the drives were used in NEC's Mate desktop PC series, sold to enterprise users. The company has been contacting clients about the fault since last October.
Other drives were used in NEC's Value Star series of consumer desktop PCs. NEC made an announcement on its Web site on 9 September, offering free replacement upon request.
In July, Fujitsu started recalling its own affected desktop PCs and PC servers, the FMV desktop PC series and the IA server Primergy series.
Japanese media reports have estimated that the recalls would have cost Fujitsu more than £53m.
"We haven't figured out how many units the company has replaced so far. However, we don't expect the cost will be that much," a Fujitsu spokesman said.