In 1998, Halliwell left the Spice Girls due to natural depression and differences between the group. The next year, she launched her solo career and released her debut album Schizophonic, with the lead single "Look at Me", produced by Absolute and Phil Bucknall. "Look at Me" was followed by further number ones at the UK Singles Chart "Mi Chico Latino", "Lift Me Up", and "Bag It Up". The album itself reached a peak at number four in the United Kingdom, and sold 600,000 copies there, making it 2× Platinum. With only a radio single, Schizophonic debuted at number forty-two on the Billboard 200 before dropping out within the next month. The album was eventually certified Gold, distributing over 500,000 copies.Schizophonic ended up selling around 2,300,000 copies worldwide, and remains Halliwell's biggest selling album to date.
Halliwell described the album as "bright and colourful"; The album includes a cover version of The Weather Girls' "It's Raining Men" (1983), which became Halliwell's fourth UK number-one hit single.
Halliwell commented about the album: "There's deeper meaning underneath if you care and choose to look. Some of it is deep as a puddle, some of it is a bottomless pit, like a well".
The album's artwork depicts Halliwell on roller skates, holding onto the back of a Cadillac. However, on 21 April 2001, The Sun newspaper claimed that the picture was setting a bad example to children. Road safety campaigners argue that the image could put children's lives at risk, according to the newspaper. Jane Eason of the Royal Society for the Prevention of Accidents said, "This seems like very irresponsible behaviour from someone like Geri Halliwell. We are very concerned about kids playing with roller skates, micro scooters or skateboards anywhere near roads, never mind hanging onto the back of cars. We had a lot of problems a few years ago with the film Back To The Future when similar tricks were used. Considering Geri Halliwell has only recently been banned from driving, I think it is very wrong of her to encourage this kind of thing." Jane Eason's words were echoed by Mary Williams of road safety organisation Brake. "We have most accidents of this type in the ten to 14-year-old age range, and particularly among 12-year-olds who play on in-line skates and micro scooters. Kids playing in the road is probably the most neglected area of road safety and it is causing fatal accidents every year. Geri Halliwell is an icon for young children and our worry is that kids will be tempted to copy her. I would have hoped that Geri and her advisers would have had a little foresight into the possible consequences of such a message". A spokesman for Halliwell said, "It's amazing the cover is being taken so seriously. It's just meant to be a bright, fun image".
Scream If You Wanna Go Faster sold 9,000 copies on its first day of release,
Although not as successful as her debut album Schizophonic, it reached a peak position of number five on the UK Albums Chart. With first-week sales of 35,000 copies and total sales of 155,000, it became the 127th best selling album of 2001 in the United Kingdom. Sales in the United Kingdom ensured Gold status.