Visitors to the Highlanders' Museum will only be able to see 80% of its extensive collection when it reopens.
The museum in Fort George closed on the 18 March, along with other tourist attractions across Scotland, due to the coronavirus pandemic.
Staff have been working on measures to make sure the museum can reopen safely.
But Major (Retired) Maurice Gibson, chairman of the museum, said he was disappointed that not all of the exhibitions can be displayed due to the building's structure.
"[Visitors are] going to see about 80% of the collection, and I'm disappointed that we can't get them to the top floor or indeed to the temporary exhibition and the initial display downstairs but the geography within the building doesn't allow that," he said.
The museum covers the period from the Battle of Culloden to the present day and includes artefacts from the Seaforth Highlanders, The Queen’s Own Cameron Highlanders, the Queen’s Own Highlanders, The Highlanders, and 4th Battalion The Royal Regiment of Scotland.
During a typical summer, the museum attracts around 50,000 visitors.
But numbers will now be limited by a pre-booking system available on the museum's website.
Face coverings will also have to be worn.
Maj Gibson said the measures are "crucial not just for my staff [but] for the visitors and the experience that they get".
A one-way system and hand-sanitising stations have also been put in place, including at interactive touch screen exhibitions.
Ernie Pope, research and volunteer co-ordinator at the museum said: "We'e relying on people to be adult about this.
"We initially planned to switch these [touch screens] off and that way it would be 100% safe but it's such an important aspect."
Some of the exhibitions have been in storage for months, including a collection that has returned from Canada and was due to go on display in the spring.
Laura MacCalman, the museum's curator, said: "It's not normal to have a museum with all these wonderful objects on display, closed to the public and people not appreciating them and getting enjoyment out of our collections.
"We're really excited to be able to welcome people back."