You don't necessarily need to delete e-mail attachments to recover some hard drive space. Here are some things you can try:
The most obvious solution is to delete useless and obsolete files. Windows XP comes with a disk cleanup utility, appropriately called “Disk Cleanup.” To access it, go to Start Menu > All Programs > Accessories > System Tools > Disk Cleanup. A new window will appear, be sure to check: Download Program Files, Temporary Internet Files, Offline Webpages, Microsoft Error Reporting Temporary Files, Recycle Bin and Temporary Files. You can elect to include Compress Files. This last option does not delete files; instead, it compresses old files. You can see the list of files which will be deleted by clicking [View Files].
After cleaning the hard drive, you should also defrag your hard drive. Oftentimes, files are saved on different sectors on a hard drive. You can consolidate the files and decrease the gaps between them by using Windows XP’s Disk Defragmenter. To access it, go to Start Menu > All Programs > Accessories > System Tools > Disk Defragmenter. A new window will appear. Click [Analyze] to see if your hard drive needs to be defragmented. If so, click [Defragment] to begin the process. The process can take minutes and even hours depending on the degree of fragmentation on the disk.
Besides deleting temporary Internet files, you can also decrease the size of Internet Explorer (IE) disk cache. The default setting is 1024 MB (1.0 GB). Start IE and, from the menu bar, go to Tools > Internet Options > “General” tab > [Settings] > under disk space, enter a value of 50 – 150 MB.
Windows XP comes with a backup utility, System Restore. System Restore creates backups of the registry. It comes in handy when your system crashes. System Restore can roll your computer back to a healthy state. By default, System Restore can commandeer up to 12% of your hard drive space. Most users don’t need such a tremendous amount of space. You can manually adjust the amount of space allocated to System Restore. Right click the “My Computer” icon and select Properties > “System Restore” tab > under Disk space usage, slide the bar back to a more reasonable 3% > [Apply] > [O.K.].