Frequent trains from London Waterloo Station to Winchester take approximately 1 hour and run hourly (more often at peak times).
There is a shuttle bus service from Heathrow Airport to Woking Station which connects with most London–Winchester trains. Look for “RailLink”, buy ticket on bus and be prepared for up to 1 hour wait at Woking. Journey time to Winchester is between 1.5 and 2.5 hours depending on your luck!
Some trains also stop at London Clapham Junction offering rail connections from Gatwick Airport.
IBM Hursley is approximately 15 minutes by taxi from Winchester Station.
A bus service runs from Winchester, via Hursley to Romsey. The number 66 bus (labelled Romsey) leaves the Winchester Bus Station hourly (approx) and it takes about 20 minutes to reach Hursley Village. On alighting at the Hursley village Post Office, cross over the road, walk up the path behind the church and then follow signs to IBM reception.