Buying a computer for your business is a lot like going to the doctor: you know it's necessary, but you put off doing it as long as you can.

But purchasing a new PC -- or a load of PCs for your staff -- doesn't need to be a difficult process, so long as you understand your company's computing needs and budget. "One of the common challenges for a growing business is coming up with a standardized IT environment, picking a platform and sticking with it for a relatively long period of time," says Bob O'Donnell, program vice president for clients and displays at IDC, an Internet technologies consultant. "Businesses need a plan in place for adding, replacing or upgrading machines, so it's a relatively painless process."

When investing in computers for your business, the trick is to ask yourself a few simple questions before you make the purchase -- and then ask a few more of the manufacturer or retailer, says O'Donnell. The following are a handful of such questions, tips, and suggestions.

Stable image platforms

Depending on the size of your business, having a pre-installed "image platform" that includes all the key programs your employees need can make this process a smoother one. "Image platform" refers to the bundling of software and hardware programs by the manufacturer in the machine you purchase.

"Some PC vendors are better at this than others, but having the software you need pre-installed is very handy," says O'Donnell. CUT FOR LACK OF CLARITY

Portability

Another important consideration is whether or not you need a mobile PC. A laptop is generally more expensive than a desktop computer, and more can go wrong because of its smaller components. But you can easily take laptops with you from place to place. If you're buying PCs for four of your sales people who live on the road, then you can figure out the answer to this problem.

"It's not rocket science -- it boils down to what's right for your users," says Michael Gartenberg, vice president and research director for Jupiter Research. "If you're a mobile user, you might not need desktops. But if you never leave the office, you don't need to invest in notebooks."

Windows vs. Macs

Because Windows has an estimated 95 percent market share (depending on whom you ask), the advantage here is generally cheaper prices because of increased competition among hardware manufacturers. Plus, more software is available for Windows users.

O'Donnell agrees: "Macs can be reasonable business PCs, but there's concern about software not being there, such as CRM options. And some companies write their own custom applications and it tends to be on the Windows platform."

Still, the Mac offers core business applications and, crucially, is less prone to viruses and hackers.

No name vs. brand name

Computers are often cheaper when purchased from local stores and lesser-known manufacturers. But, generally speaking, these no-name PCs do not come with as comprehensive a warranty or return policy as the brand-name players, nor would their tech support department likely be as thorough. However, if you consider yourself tech-savvy, then a no-name PC may be for you.

O'Donnell says a bigger company may want to pay for the assurance the vendor will be there when they need it. "If your CEO is traveling on the weekend and he needs his machine fixed, will he find a place that can take care of it?"

Components

Just as a mom will tell you it's wisest to buy clothes a tad bigger for kids so they can grow into them, the same goes for shopping for a PC: spend a bit more on its components and features so it will last a long time. In other words, buy a Gigabyte of system memory even though your programs today require only 512MB. Pick up a dual-core processor instead of one CPU. Figure out what you need out of a PC and buy a little beyond that, with your eye on company growth.

"You need to future-proof your purchase as much as you can," says Gartenberg. "Not only do you need to figure out what the computer is used for today, but also tomorrow. Try to factor in future upgrades such as Windows Vista."

Networking

Chances are the PCs you pick up for the office -- whether it's just one for you or new machines for all -- will need to be connected, not just to the Internet, but to each other over your corporate intranet. Therefore, make sure your PC has integrated wired LAN (and preferably wireless LAN) functionality. This should be the case with any PC you buy today, but double-check that the PCs you select are network-ready. Probably half of what you need out of a computer today is stored on the PC's hard drive, with the other half residing in cyberspace.

"You may also want laptops with integrated wireless WAN, wide-area networking, that works with cellular data plans," adds O'Donnell. "You pay a premium for this service. But you can log on virtually anywhere using a cell connection, instead of having to hunt for a hotspot."

New vs. used

Purchasing a second-hand PC -- from a colleague, online auction site or refurbished by a computer company -- is a consideration for those very tight on cash. But just like a used car, a "previously enjoyed" PC could very well come with its share of problems. The short answer? Don't buy used. This may be fine for other office equipment, such as desks, but not for something as important as a PC.

Warranty, support

Be sure to carefully read the warranty and support offered by the computer manufacturer. For example, is the warranty for both parts and service? And for how long? Do they replace parts or fix them? Will you get dinged for on-site service or shipping costs? Does your monitor fall under the same warranty as the tower and everything in it? Is the tech support phone number free? Are they open 24/7?

Caveat Emptor

Hundreds of reputable computer magazines and Web sites rate and review new PCs and their components, so be sure to do your homework beforehand. While many benchmark their performance in controlled labs, you might just be interested in what features it has, what it may be missing, and how it compares to other PCs with the same price tag.