While cleaning out an old drawer recently, I unearthed a floppy disk. I blew off the dust and smiled at the little plastic square. I wondered what this disk could possibly contain. At some point, certain technology isn’t useful anymore.

Don’t let manufacturers trick you into buying something you don’t need. Here are five dubious tech money-wasters and how to avoid them.

1. Computer tuneup software

An ad pops up on your computer: “Slow PC? Get a Free PC Tuneup!” There’s a simple graphic and a phone number. Every computer could use a tuneup, right? Making sure your computer is running smoothly is just part of being a responsible user. So why not go for it?

Hold the phone! Tuneup software is great, but you don’t have to pay for it. Many people don’t realize this. They shell out money for software that’s available for free, or they click the wrong banner ad for a subpar service.

Let me save you some time: Try Wise Care 365. It’s quick to download, the features are easy to use and you can scan your PC in under a minute. When it’s finished, the PC Checkup feature will grade your computer on a 1-10 scale, indicating how sick or healthy it is.

Another helpful tool is IObit Uninstaller, which helps you free up space on your PC. Its Advanced SystemCare feature can optimize an older computer by up to 300 percent. The software deletes junk files, clears out private information and disables unneeded startup items. Think of it as a deep cleanse for your hard drive.

Your PC could be loaded with malware or spyware that will definitely slow things down. To find out, use Malwarebytes. It's capable of finding and removing threats that other software misses. Plus, the free version won't conflict with your existing antivirus. Click here to get this great free download now.

Before you use any of these programs, practice safe computing. Make sure you have a backup.

2. Renting a router or modem

Renting your internet hardware used to be very common. Your router would arrive in a box, or maybe a technician would come over to set up your modem. A few years later, you’d pack up the equipment and ship it back to your service provider, never realizing that you essentially paid double for it.

Nowadays, renting these devices can be a waste of money. It’s like buying popcorn at the movie theater: You may appreciate the convenience, but it’s way overpriced and serves only to make the company extra money. You can find a very decent router through Best Buy or Amazon for under $100, and you won’t have to shell out $8-10 every month for the privilege of using it.

Better yet, buy your router based on the features you want. Not all routers are created equal. Some are faster; others provide better security. Click here for my three best router recommendations.

There are a few considerations, though. First, your internet service provider may not let you use a store-bought router or modem. Second, you may have to figure out how to install the devices yourself, and not everybody wants to deal with that. Finally, do you expect to use the same service provider for more than a year?

The same advice applies to your modem. You’re better off buying that too. Click here for advice on buying the best modem.

3. Cables that cost more than $15

Five hours into your road trip, you realize you left your Lightning wire back home. Your iPhone is losing battery fast, and you absolutely have to pick up a new one. When you arrive at a generic drug store, you find one that costs $30. You raise an eyebrow. Is that normal?

Here’s my rule of thumb: If you’re paying more than $15 for a single cable, you’re paying too much. In my experience, a cable costing more than that doesn’t offer any extra quality or performance. Some cables are better marketed than others, but the bottom line is: A cable is a cable.

Be particularly suspicious of HDMI cables. Some cost under $10; others are priced at nearly $100. But I have never found any significant difference between one type and another.

There’s just one exception: third-party cables for specific devices. Take our first example, the Lightning wire. Ideally, you would be able to find an Apple Store and pay the $19 for the real thing. A third-party iPhone charger may work in a pinch, but it may also cause damage to your phone or even start a fire.

4. Car GPS and traffic subscriptions

As more cars are manufactured with built-in screens, customers like the idea of an entertainment console right next to their steering wheel. But it begs the question: Do you need to subscribe to the company’s GPS or virtual traffic reports?

If you have a smartphone, the answer is no. These subscriptions are lucrative for the car companies, but they’re completely unnecessary if you have a compatible iPhone or Android. Simply plug the device into your car and you can use all your regular navigation apps through that same built-in console.

You can use regular services like Google Maps, Here Maps or Waze, which will help you get around easily. Just one hitch: Using GPS regularly can drain your data plan. But I find it much less expensive than paying for an extra service.

5. Crowdfunded pre-orders

I admit, it’s fun to browse Kickstarter and IndieGoGo projects. You’ll find all sorts of gizmos-in-the-making, with clever videos and enthusiastic descriptions. The breadth of imagination is inspiring, especially when some tinkerer solves a problem you didn’t even know you had.

Pre-ordering a new piece of technology can feel exciting and cutting-edge, so it pains me to dissuade you from doing this. Supporting a crowd-sourced project is a total gamble. Even if the underfunded inventor meets his goal, backers have no idea how he’ll spend the money. There’s no accountability.

An infamous example was Central Standard Timing, which raised $1 million on Kickstarter to manufacture the “world’s thinnest watch.” The company failed, and many critics believed it was a scam. But backers didn’t feel they had any recourse. How can you expect to receive a pre-ordered item if the company goes under? How can you check up on the entrepreneurs if you don’t really know who they are?

If you want to donate to a worthy cause, you’re better off finding an established, well-run charitable organization or scholarship program. Now that is money well spent.

How else can you protect yourself from digital danger? Be sure to listen to or download my podcasts, or click here to find it on your local radio station. You can listen to the Kim Komando Show on your phone, tablet or computer. From buying advice to digital life issues, click here for my free podcasts.

Copyright 2017, WestStar Multimedia Entertainment. All rights reserved.

Learn about all the latest technology on the Kim Komando Show, the nation's largest weekend radio talk show. Kim takes calls and dispenses advice on today's digital lifestyle, from smartphones and tablets to online privacy and data hacks. For her daily tips, free newsletters and more, visit her website at Komando.com.