Witnesses described him as white, with tattoos, while police later confirmed they had arrested a 48-year-old on suspicion of attempted murder, they added they were not looking for anyone else.
Darren Osborne, a 47-year-old father of four from Wales, was identified by British media Monday as the country recovers from what the country's authorities are treating as the third terrorist incident in less than a month.
The alleged attacker is now in custody, and a residence in Cardiff, Wales, is being inspected by the police as possibly associated with the incident.
The attack comes just over two weeks after three Islamist militants drove into pedestrians on London Bridge and stabbed people at nearby restaurants and bars, killing eight.
Eight people remain in hospital after the incident.
It is understood he rammed into a crowd of worshippers who were helping a man who'd collapsed.
The imam of Muslim Welfare House - which is also a community centre - said a passing police van was flagged down after the attack.
"There was a mob attempt to hurt him, so we pushed people away from him until he was safely taken by police", he added.
However, the incident is being treated as a terror attack.
Sarah Mushtaq said attacks like what happened in London can create some fear within the Muslim community in Windsor.
A suicide bombing at a pop concert in Manchester, northern England, in May also killed 22 people, while in March, a man drove a rented vehicle into pedestrians on Westminster Bridge in London and stabbed a policeman to death before being shot dead.
There were more angry scenes as police arrived and protected the accused man as he was put into a police vehicle.
He said: "I couldn t believe when I realised it was him who was accused".
Neighbour Khadijeh Sherizi said: "I saw him on the news and I thought "oh my God" that is my neighbour".
The Muslim Council also demand more security for the worshipping spaces, having stated that the earlier attack was another extreme demonstration of Islamophobia. Police said extra personnel had been deployed to reassure Muslim communities in London and security outside mosques would be reviewed.